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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_CUR 1024	/* Initial setting for nfile rlimits */
27 #define INR_OPEN_MAX 4096	/* Hard limit for nfile rlimits */
28 
29 #define BLOCK_SIZE_BITS 10
30 #define BLOCK_SIZE (1<<BLOCK_SIZE_BITS)
31 
32 #define SEEK_SET	0	/* seek relative to beginning of file */
33 #define SEEK_CUR	1	/* seek relative to current file position */
34 #define SEEK_END	2	/* seek relative to end of file */
35 #define SEEK_MAX	SEEK_END
36 
37 struct fstrim_range {
38 	__u64 start;
39 	__u64 len;
40 	__u64 minlen;
41 };
42 
43 /* And dynamically-tunable limits and defaults: */
44 struct files_stat_struct {
45 	unsigned long nr_files;		/* read only */
46 	unsigned long nr_free_files;	/* read only */
47 	unsigned long max_files;		/* tunable */
48 };
49 
50 struct inodes_stat_t {
51 	int nr_inodes;
52 	int nr_unused;
53 	int dummy[5];		/* padding for sysctl ABI compatibility */
54 };
55 
56 
57 #define NR_FILE  8192	/* this can well be larger on a larger system */
58 
59 #define MAY_EXEC 1
60 #define MAY_WRITE 2
61 #define MAY_READ 4
62 #define MAY_APPEND 8
63 #define MAY_ACCESS 16
64 #define MAY_OPEN 32
65 #define MAY_CHDIR 64
66 
67 /*
68  * flags in file.f_mode.  Note that FMODE_READ and FMODE_WRITE must correspond
69  * to O_WRONLY and O_RDWR via the strange trick in __dentry_open()
70  */
71 
72 /* file is open for reading */
73 #define FMODE_READ		((__force fmode_t)0x1)
74 /* file is open for writing */
75 #define FMODE_WRITE		((__force fmode_t)0x2)
76 /* file is seekable */
77 #define FMODE_LSEEK		((__force fmode_t)0x4)
78 /* file can be accessed using pread */
79 #define FMODE_PREAD		((__force fmode_t)0x8)
80 /* file can be accessed using pwrite */
81 #define FMODE_PWRITE		((__force fmode_t)0x10)
82 /* File is opened for execution with sys_execve / sys_uselib */
83 #define FMODE_EXEC		((__force fmode_t)0x20)
84 /* File is opened with O_NDELAY (only set for block devices) */
85 #define FMODE_NDELAY		((__force fmode_t)0x40)
86 /* File is opened with O_EXCL (only set for block devices) */
87 #define FMODE_EXCL		((__force fmode_t)0x80)
88 /* File is opened using open(.., 3, ..) and is writeable only for ioctls
89    (specialy hack for floppy.c) */
90 #define FMODE_WRITE_IOCTL	((__force fmode_t)0x100)
91 
92 /*
93  * Don't update ctime and mtime.
94  *
95  * Currently a special hack for the XFS open_by_handle ioctl, but we'll
96  * hopefully graduate it to a proper O_CMTIME flag supported by open(2) soon.
97  */
98 #define FMODE_NOCMTIME		((__force fmode_t)0x800)
99 
100 /* Expect random access pattern */
101 #define FMODE_RANDOM		((__force fmode_t)0x1000)
102 
103 /* File is huge (eg. /dev/kmem): treat loff_t as unsigned */
104 #define FMODE_UNSIGNED_OFFSET	((__force fmode_t)0x2000)
105 
106 /* File is opened with O_PATH; almost nothing can be done with it */
107 #define FMODE_PATH		((__force fmode_t)0x4000)
108 
109 /* File was opened by fanotify and shouldn't generate fanotify events */
110 #define FMODE_NONOTIFY		((__force fmode_t)0x1000000)
111 
112 /*
113  * The below are the various read and write types that we support. Some of
114  * them include behavioral modifiers that send information down to the
115  * block layer and IO scheduler. Terminology:
116  *
117  *	The block layer uses device plugging to defer IO a little bit, in
118  *	the hope that we will see more IO very shortly. This increases
119  *	coalescing of adjacent IO and thus reduces the number of IOs we
120  *	have to send to the device. It also allows for better queuing,
121  *	if the IO isn't mergeable. If the caller is going to be waiting
122  *	for the IO, then he must ensure that the device is unplugged so
123  *	that the IO is dispatched to the driver.
124  *
125  *	All IO is handled async in Linux. This is fine for background
126  *	writes, but for reads or writes that someone waits for completion
127  *	on, we want to notify the block layer and IO scheduler so that they
128  *	know about it. That allows them to make better scheduling
129  *	decisions. So when the below references 'sync' and 'async', it
130  *	is referencing this priority hint.
131  *
132  * With that in mind, the available types are:
133  *
134  * READ			A normal read operation. Device will be plugged.
135  * READ_SYNC		A synchronous read. Device is not plugged, caller can
136  *			immediately wait on this read without caring about
137  *			unplugging.
138  * READA		Used for read-ahead operations. Lower priority, and the
139  *			block layer could (in theory) choose to ignore this
140  *			request if it runs into resource problems.
141  * WRITE		A normal async write. Device will be plugged.
142  * WRITE_SYNC		Synchronous write. Identical to WRITE, but passes down
143  *			the hint that someone will be waiting on this IO
144  *			shortly. The write equivalent of READ_SYNC.
145  * WRITE_ODIRECT	Special case write for O_DIRECT only.
146  * WRITE_FLUSH		Like WRITE_SYNC but with preceding cache flush.
147  * WRITE_FUA		Like WRITE_SYNC but data is guaranteed to be on
148  *			non-volatile media on completion.
149  * WRITE_FLUSH_FUA	Combination of WRITE_FLUSH and FUA. The IO is preceded
150  *			by a cache flush and data is guaranteed to be on
151  *			non-volatile media on completion.
152  *
153  */
154 #define RW_MASK			REQ_WRITE
155 #define RWA_MASK		REQ_RAHEAD
156 
157 #define READ			0
158 #define WRITE			RW_MASK
159 #define READA			RWA_MASK
160 
161 #define READ_SYNC		(READ | REQ_SYNC)
162 #define READ_META		(READ | REQ_META)
163 #define WRITE_SYNC		(WRITE | REQ_SYNC | REQ_NOIDLE)
164 #define WRITE_ODIRECT		(WRITE | REQ_SYNC)
165 #define WRITE_META		(WRITE | REQ_META)
166 #define WRITE_FLUSH		(WRITE | REQ_SYNC | REQ_NOIDLE | REQ_FLUSH)
167 #define WRITE_FUA		(WRITE | REQ_SYNC | REQ_NOIDLE | REQ_FUA)
168 #define WRITE_FLUSH_FUA		(WRITE | REQ_SYNC | REQ_NOIDLE | REQ_FLUSH | REQ_FUA)
169 
170 #define SEL_IN		1
171 #define SEL_OUT		2
172 #define SEL_EX		4
173 
174 /* public flags for file_system_type */
175 #define FS_REQUIRES_DEV 1
176 #define FS_BINARY_MOUNTDATA 2
177 #define FS_HAS_SUBTYPE 4
178 #define FS_REVAL_DOT	16384	/* Check the paths ".", ".." for staleness */
179 #define FS_RENAME_DOES_D_MOVE	32768	/* FS will handle d_move()
180 					 * during rename() internally.
181 					 */
182 
183 /*
184  * These are the fs-independent mount-flags: up to 32 flags are supported
185  */
186 #define MS_RDONLY	 1	/* Mount read-only */
187 #define MS_NOSUID	 2	/* Ignore suid and sgid bits */
188 #define MS_NODEV	 4	/* Disallow access to device special files */
189 #define MS_NOEXEC	 8	/* Disallow program execution */
190 #define MS_SYNCHRONOUS	16	/* Writes are synced at once */
191 #define MS_REMOUNT	32	/* Alter flags of a mounted FS */
192 #define MS_MANDLOCK	64	/* Allow mandatory locks on an FS */
193 #define MS_DIRSYNC	128	/* Directory modifications are synchronous */
194 #define MS_NOATIME	1024	/* Do not update access times. */
195 #define MS_NODIRATIME	2048	/* Do not update directory access times */
196 #define MS_BIND		4096
197 #define MS_MOVE		8192
198 #define MS_REC		16384
199 #define MS_VERBOSE	32768	/* War is peace. Verbosity is silence.
200 				   MS_VERBOSE is deprecated. */
201 #define MS_SILENT	32768
202 #define MS_POSIXACL	(1<<16)	/* VFS does not apply the umask */
203 #define MS_UNBINDABLE	(1<<17)	/* change to unbindable */
204 #define MS_PRIVATE	(1<<18)	/* change to private */
205 #define MS_SLAVE	(1<<19)	/* change to slave */
206 #define MS_SHARED	(1<<20)	/* change to shared */
207 #define MS_RELATIME	(1<<21)	/* Update atime relative to mtime/ctime. */
208 #define MS_KERNMOUNT	(1<<22) /* this is a kern_mount call */
209 #define MS_I_VERSION	(1<<23) /* Update inode I_version field */
210 #define MS_STRICTATIME	(1<<24) /* Always perform atime updates */
211 #define MS_NOSEC	(1<<28)
212 #define MS_BORN		(1<<29)
213 #define MS_ACTIVE	(1<<30)
214 #define MS_NOUSER	(1<<31)
215 
216 /*
217  * Superblock flags that can be altered by MS_REMOUNT
218  */
219 #define MS_RMT_MASK	(MS_RDONLY|MS_SYNCHRONOUS|MS_MANDLOCK|MS_I_VERSION)
220 
221 /*
222  * Old magic mount flag and mask
223  */
224 #define MS_MGC_VAL 0xC0ED0000
225 #define MS_MGC_MSK 0xffff0000
226 
227 /* Inode flags - they have nothing to superblock flags now */
228 
229 #define S_SYNC		1	/* Writes are synced at once */
230 #define S_NOATIME	2	/* Do not update access times */
231 #define S_APPEND	4	/* Append-only file */
232 #define S_IMMUTABLE	8	/* Immutable file */
233 #define S_DEAD		16	/* removed, but still open directory */
234 #define S_NOQUOTA	32	/* Inode is not counted to quota */
235 #define S_DIRSYNC	64	/* Directory modifications are synchronous */
236 #define S_NOCMTIME	128	/* Do not update file c/mtime */
237 #define S_SWAPFILE	256	/* Do not truncate: swapon got its bmaps */
238 #define S_PRIVATE	512	/* Inode is fs-internal */
239 #define S_IMA		1024	/* Inode has an associated IMA struct */
240 #define S_AUTOMOUNT	2048	/* Automount/referral quasi-directory */
241 #define S_NOSEC		4096	/* no suid or xattr security attributes */
242 
243 /*
244  * Note that nosuid etc flags are inode-specific: setting some file-system
245  * flags just means all the inodes inherit those flags by default. It might be
246  * possible to override it selectively if you really wanted to with some
247  * ioctl() that is not currently implemented.
248  *
249  * Exception: MS_RDONLY is always applied to the entire file system.
250  *
251  * Unfortunately, it is possible to change a filesystems flags with it mounted
252  * with files in use.  This means that all of the inodes will not have their
253  * i_flags updated.  Hence, i_flags no longer inherit the superblock mount
254  * flags, so these have to be checked separately. -- rmk@arm.uk.linux.org
255  */
256 #define __IS_FLG(inode,flg) ((inode)->i_sb->s_flags & (flg))
257 
258 #define IS_RDONLY(inode) ((inode)->i_sb->s_flags & MS_RDONLY)
259 #define IS_SYNC(inode)		(__IS_FLG(inode, MS_SYNCHRONOUS) || \
260 					((inode)->i_flags & S_SYNC))
261 #define IS_DIRSYNC(inode)	(__IS_FLG(inode, MS_SYNCHRONOUS|MS_DIRSYNC) || \
262 					((inode)->i_flags & (S_SYNC|S_DIRSYNC)))
263 #define IS_MANDLOCK(inode)	__IS_FLG(inode, MS_MANDLOCK)
264 #define IS_NOATIME(inode)   __IS_FLG(inode, MS_RDONLY|MS_NOATIME)
265 #define IS_I_VERSION(inode)   __IS_FLG(inode, MS_I_VERSION)
266 
267 #define IS_NOQUOTA(inode)	((inode)->i_flags & S_NOQUOTA)
268 #define IS_APPEND(inode)	((inode)->i_flags & S_APPEND)
269 #define IS_IMMUTABLE(inode)	((inode)->i_flags & S_IMMUTABLE)
270 #define IS_POSIXACL(inode)	__IS_FLG(inode, MS_POSIXACL)
271 
272 #define IS_DEADDIR(inode)	((inode)->i_flags & S_DEAD)
273 #define IS_NOCMTIME(inode)	((inode)->i_flags & S_NOCMTIME)
274 #define IS_SWAPFILE(inode)	((inode)->i_flags & S_SWAPFILE)
275 #define IS_PRIVATE(inode)	((inode)->i_flags & S_PRIVATE)
276 #define IS_IMA(inode)		((inode)->i_flags & S_IMA)
277 #define IS_AUTOMOUNT(inode)	((inode)->i_flags & S_AUTOMOUNT)
278 #define IS_NOSEC(inode)		((inode)->i_flags & S_NOSEC)
279 
280 /* the read-only stuff doesn't really belong here, but any other place is
281    probably as bad and I don't want to create yet another include file. */
282 
283 #define BLKROSET   _IO(0x12,93)	/* set device read-only (0 = read-write) */
284 #define BLKROGET   _IO(0x12,94)	/* get read-only status (0 = read_write) */
285 #define BLKRRPART  _IO(0x12,95)	/* re-read partition table */
286 #define BLKGETSIZE _IO(0x12,96)	/* return device size /512 (long *arg) */
287 #define BLKFLSBUF  _IO(0x12,97)	/* flush buffer cache */
288 #define BLKRASET   _IO(0x12,98)	/* set read ahead for block device */
289 #define BLKRAGET   _IO(0x12,99)	/* get current read ahead setting */
290 #define BLKFRASET  _IO(0x12,100)/* set filesystem (mm/filemap.c) read-ahead */
291 #define BLKFRAGET  _IO(0x12,101)/* get filesystem (mm/filemap.c) read-ahead */
292 #define BLKSECTSET _IO(0x12,102)/* set max sectors per request (ll_rw_blk.c) */
293 #define BLKSECTGET _IO(0x12,103)/* get max sectors per request (ll_rw_blk.c) */
294 #define BLKSSZGET  _IO(0x12,104)/* get block device sector size */
295 #if 0
296 #define BLKPG      _IO(0x12,105)/* See blkpg.h */
297 
298 /* Some people are morons.  Do not use sizeof! */
299 
300 #define BLKELVGET  _IOR(0x12,106,size_t)/* elevator get */
301 #define BLKELVSET  _IOW(0x12,107,size_t)/* elevator set */
302 /* This was here just to show that the number is taken -
303    probably all these _IO(0x12,*) ioctls should be moved to blkpg.h. */
304 #endif
305 /* A jump here: 108-111 have been used for various private purposes. */
306 #define BLKBSZGET  _IOR(0x12,112,size_t)
307 #define BLKBSZSET  _IOW(0x12,113,size_t)
308 #define BLKGETSIZE64 _IOR(0x12,114,size_t)	/* return device size in bytes (u64 *arg) */
309 #define BLKTRACESETUP _IOWR(0x12,115,struct blk_user_trace_setup)
310 #define BLKTRACESTART _IO(0x12,116)
311 #define BLKTRACESTOP _IO(0x12,117)
312 #define BLKTRACETEARDOWN _IO(0x12,118)
313 #define BLKDISCARD _IO(0x12,119)
314 #define BLKIOMIN _IO(0x12,120)
315 #define BLKIOOPT _IO(0x12,121)
316 #define BLKALIGNOFF _IO(0x12,122)
317 #define BLKPBSZGET _IO(0x12,123)
318 #define BLKDISCARDZEROES _IO(0x12,124)
319 #define BLKSECDISCARD _IO(0x12,125)
320 
321 #define BMAP_IOCTL 1		/* obsolete - kept for compatibility */
322 #define FIBMAP	   _IO(0x00,1)	/* bmap access */
323 #define FIGETBSZ   _IO(0x00,2)	/* get the block size used for bmap */
324 #define FIFREEZE	_IOWR('X', 119, int)	/* Freeze */
325 #define FITHAW		_IOWR('X', 120, int)	/* Thaw */
326 #define FITRIM		_IOWR('X', 121, struct fstrim_range)	/* Trim */
327 
328 #define	FS_IOC_GETFLAGS			_IOR('f', 1, long)
329 #define	FS_IOC_SETFLAGS			_IOW('f', 2, long)
330 #define	FS_IOC_GETVERSION		_IOR('v', 1, long)
331 #define	FS_IOC_SETVERSION		_IOW('v', 2, long)
332 #define FS_IOC_FIEMAP			_IOWR('f', 11, struct fiemap)
333 #define FS_IOC32_GETFLAGS		_IOR('f', 1, int)
334 #define FS_IOC32_SETFLAGS		_IOW('f', 2, int)
335 #define FS_IOC32_GETVERSION		_IOR('v', 1, int)
336 #define FS_IOC32_SETVERSION		_IOW('v', 2, int)
337 
338 /*
339  * Inode flags (FS_IOC_GETFLAGS / FS_IOC_SETFLAGS)
340  */
341 #define	FS_SECRM_FL			0x00000001 /* Secure deletion */
342 #define	FS_UNRM_FL			0x00000002 /* Undelete */
343 #define	FS_COMPR_FL			0x00000004 /* Compress file */
344 #define FS_SYNC_FL			0x00000008 /* Synchronous updates */
345 #define FS_IMMUTABLE_FL			0x00000010 /* Immutable file */
346 #define FS_APPEND_FL			0x00000020 /* writes to file may only append */
347 #define FS_NODUMP_FL			0x00000040 /* do not dump file */
348 #define FS_NOATIME_FL			0x00000080 /* do not update atime */
349 /* Reserved for compression usage... */
350 #define FS_DIRTY_FL			0x00000100
351 #define FS_COMPRBLK_FL			0x00000200 /* One or more compressed clusters */
352 #define FS_NOCOMP_FL			0x00000400 /* Don't compress */
353 #define FS_ECOMPR_FL			0x00000800 /* Compression error */
354 /* End compression flags --- maybe not all used */
355 #define FS_BTREE_FL			0x00001000 /* btree format dir */
356 #define FS_INDEX_FL			0x00001000 /* hash-indexed directory */
357 #define FS_IMAGIC_FL			0x00002000 /* AFS directory */
358 #define FS_JOURNAL_DATA_FL		0x00004000 /* Reserved for ext3 */
359 #define FS_NOTAIL_FL			0x00008000 /* file tail should not be merged */
360 #define FS_DIRSYNC_FL			0x00010000 /* dirsync behaviour (directories only) */
361 #define FS_TOPDIR_FL			0x00020000 /* Top of directory hierarchies*/
362 #define FS_EXTENT_FL			0x00080000 /* Extents */
363 #define FS_DIRECTIO_FL			0x00100000 /* Use direct i/o */
364 #define FS_NOCOW_FL			0x00800000 /* Do not cow file */
365 #define FS_RESERVED_FL			0x80000000 /* reserved for ext2 lib */
366 
367 #define FS_FL_USER_VISIBLE		0x0003DFFF /* User visible flags */
368 #define FS_FL_USER_MODIFIABLE		0x000380FF /* User modifiable flags */
369 
370 
371 #define SYNC_FILE_RANGE_WAIT_BEFORE	1
372 #define SYNC_FILE_RANGE_WRITE		2
373 #define SYNC_FILE_RANGE_WAIT_AFTER	4
374 
375 #ifdef __KERNEL__
376 
377 #include <linux/linkage.h>
378 #include <linux/wait.h>
379 #include <linux/types.h>
380 #include <linux/kdev_t.h>
381 #include <linux/dcache.h>
382 #include <linux/path.h>
383 #include <linux/stat.h>
384 #include <linux/cache.h>
385 #include <linux/list.h>
386 #include <linux/radix-tree.h>
387 #include <linux/prio_tree.h>
388 #include <linux/init.h>
389 #include <linux/pid.h>
390 #include <linux/mutex.h>
391 #include <linux/capability.h>
392 #include <linux/semaphore.h>
393 #include <linux/fiemap.h>
394 #include <linux/rculist_bl.h>
395 
396 #include <asm/atomic.h>
397 #include <asm/byteorder.h>
398 
399 struct export_operations;
400 struct hd_geometry;
401 struct iovec;
402 struct nameidata;
403 struct kiocb;
404 struct kobject;
405 struct pipe_inode_info;
406 struct poll_table_struct;
407 struct kstatfs;
408 struct vm_area_struct;
409 struct vfsmount;
410 struct cred;
411 
412 extern void __init inode_init(void);
413 extern void __init inode_init_early(void);
414 extern void __init files_init(unsigned long);
415 
416 extern struct files_stat_struct files_stat;
417 extern unsigned long get_max_files(void);
418 extern int sysctl_nr_open;
419 extern struct inodes_stat_t inodes_stat;
420 extern int leases_enable, lease_break_time;
421 
422 struct buffer_head;
423 typedef int (get_block_t)(struct inode *inode, sector_t iblock,
424 			struct buffer_head *bh_result, int create);
425 typedef void (dio_iodone_t)(struct kiocb *iocb, loff_t offset,
426 			ssize_t bytes, void *private, int ret,
427 			bool is_async);
428 
429 /*
430  * Attribute flags.  These should be or-ed together to figure out what
431  * has been changed!
432  */
433 #define ATTR_MODE	(1 << 0)
434 #define ATTR_UID	(1 << 1)
435 #define ATTR_GID	(1 << 2)
436 #define ATTR_SIZE	(1 << 3)
437 #define ATTR_ATIME	(1 << 4)
438 #define ATTR_MTIME	(1 << 5)
439 #define ATTR_CTIME	(1 << 6)
440 #define ATTR_ATIME_SET	(1 << 7)
441 #define ATTR_MTIME_SET	(1 << 8)
442 #define ATTR_FORCE	(1 << 9) /* Not a change, but a change it */
443 #define ATTR_ATTR_FLAG	(1 << 10)
444 #define ATTR_KILL_SUID	(1 << 11)
445 #define ATTR_KILL_SGID	(1 << 12)
446 #define ATTR_FILE	(1 << 13)
447 #define ATTR_KILL_PRIV	(1 << 14)
448 #define ATTR_OPEN	(1 << 15) /* Truncating from open(O_TRUNC) */
449 #define ATTR_TIMES_SET	(1 << 16)
450 
451 /*
452  * This is the Inode Attributes structure, used for notify_change().  It
453  * uses the above definitions as flags, to know which values have changed.
454  * Also, in this manner, a Filesystem can look at only the values it cares
455  * about.  Basically, these are the attributes that the VFS layer can
456  * request to change from the FS layer.
457  *
458  * Derek Atkins <warlord@MIT.EDU> 94-10-20
459  */
460 struct iattr {
461 	unsigned int	ia_valid;
462 	umode_t		ia_mode;
463 	uid_t		ia_uid;
464 	gid_t		ia_gid;
465 	loff_t		ia_size;
466 	struct timespec	ia_atime;
467 	struct timespec	ia_mtime;
468 	struct timespec	ia_ctime;
469 
470 	/*
471 	 * Not an attribute, but an auxiliary info for filesystems wanting to
472 	 * implement an ftruncate() like method.  NOTE: filesystem should
473 	 * check for (ia_valid & ATTR_FILE), and not for (ia_file != NULL).
474 	 */
475 	struct file	*ia_file;
476 };
477 
478 /*
479  * Includes for diskquotas.
480  */
481 #include <linux/quota.h>
482 
483 /**
484  * enum positive_aop_returns - aop return codes with specific semantics
485  *
486  * @AOP_WRITEPAGE_ACTIVATE: Informs the caller that page writeback has
487  * 			    completed, that the page is still locked, and
488  * 			    should be considered active.  The VM uses this hint
489  * 			    to return the page to the active list -- it won't
490  * 			    be a candidate for writeback again in the near
491  * 			    future.  Other callers must be careful to unlock
492  * 			    the page if they get this return.  Returned by
493  * 			    writepage();
494  *
495  * @AOP_TRUNCATED_PAGE: The AOP method that was handed a locked page has
496  *  			unlocked it and the page might have been truncated.
497  *  			The caller should back up to acquiring a new page and
498  *  			trying again.  The aop will be taking reasonable
499  *  			precautions not to livelock.  If the caller held a page
500  *  			reference, it should drop it before retrying.  Returned
501  *  			by readpage().
502  *
503  * address_space_operation functions return these large constants to indicate
504  * special semantics to the caller.  These are much larger than the bytes in a
505  * page to allow for functions that return the number of bytes operated on in a
506  * given page.
507  */
508 
509 enum positive_aop_returns {
510 	AOP_WRITEPAGE_ACTIVATE	= 0x80000,
511 	AOP_TRUNCATED_PAGE	= 0x80001,
512 };
513 
514 #define AOP_FLAG_UNINTERRUPTIBLE	0x0001 /* will not do a short write */
515 #define AOP_FLAG_CONT_EXPAND		0x0002 /* called from cont_expand */
516 #define AOP_FLAG_NOFS			0x0004 /* used by filesystem to direct
517 						* helper code (eg buffer layer)
518 						* to clear GFP_FS from alloc */
519 
520 /*
521  * oh the beauties of C type declarations.
522  */
523 struct page;
524 struct address_space;
525 struct writeback_control;
526 
527 struct iov_iter {
528 	const struct iovec *iov;
529 	unsigned long nr_segs;
530 	size_t iov_offset;
531 	size_t count;
532 };
533 
534 size_t iov_iter_copy_from_user_atomic(struct page *page,
535 		struct iov_iter *i, unsigned long offset, size_t bytes);
536 size_t iov_iter_copy_from_user(struct page *page,
537 		struct iov_iter *i, unsigned long offset, size_t bytes);
538 void iov_iter_advance(struct iov_iter *i, size_t bytes);
539 int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes);
540 size_t iov_iter_single_seg_count(struct iov_iter *i);
541 
iov_iter_init(struct iov_iter * i,const struct iovec * iov,unsigned long nr_segs,size_t count,size_t written)542 static inline void iov_iter_init(struct iov_iter *i,
543 			const struct iovec *iov, unsigned long nr_segs,
544 			size_t count, size_t written)
545 {
546 	i->iov = iov;
547 	i->nr_segs = nr_segs;
548 	i->iov_offset = 0;
549 	i->count = count + written;
550 
551 	iov_iter_advance(i, written);
552 }
553 
iov_iter_count(struct iov_iter * i)554 static inline size_t iov_iter_count(struct iov_iter *i)
555 {
556 	return i->count;
557 }
558 
559 /*
560  * "descriptor" for what we're up to with a read.
561  * This allows us to use the same read code yet
562  * have multiple different users of the data that
563  * we read from a file.
564  *
565  * The simplest case just copies the data to user
566  * mode.
567  */
568 typedef struct {
569 	size_t written;
570 	size_t count;
571 	union {
572 		char __user *buf;
573 		void *data;
574 	} arg;
575 	int error;
576 } read_descriptor_t;
577 
578 typedef int (*read_actor_t)(read_descriptor_t *, struct page *,
579 		unsigned long, unsigned long);
580 
581 struct address_space_operations {
582 	int (*writepage)(struct page *page, struct writeback_control *wbc);
583 	int (*readpage)(struct file *, struct page *);
584 
585 	/* Write back some dirty pages from this mapping. */
586 	int (*writepages)(struct address_space *, struct writeback_control *);
587 
588 	/* Set a page dirty.  Return true if this dirtied it */
589 	int (*set_page_dirty)(struct page *page);
590 
591 	int (*readpages)(struct file *filp, struct address_space *mapping,
592 			struct list_head *pages, unsigned nr_pages);
593 
594 	int (*write_begin)(struct file *, struct address_space *mapping,
595 				loff_t pos, unsigned len, unsigned flags,
596 				struct page **pagep, void **fsdata);
597 	int (*write_end)(struct file *, struct address_space *mapping,
598 				loff_t pos, unsigned len, unsigned copied,
599 				struct page *page, void *fsdata);
600 
601 	/* Unfortunately this kludge is needed for FIBMAP. Don't use it */
602 	sector_t (*bmap)(struct address_space *, sector_t);
603 	void (*invalidatepage) (struct page *, unsigned long);
604 	int (*releasepage) (struct page *, gfp_t);
605 	void (*freepage)(struct page *);
606 	ssize_t (*direct_IO)(int, struct kiocb *, const struct iovec *iov,
607 			loff_t offset, unsigned long nr_segs);
608 	int (*get_xip_mem)(struct address_space *, pgoff_t, int,
609 						void **, unsigned long *);
610 	/* migrate the contents of a page to the specified target */
611 	int (*migratepage) (struct address_space *,
612 			struct page *, struct page *);
613 	int (*launder_page) (struct page *);
614 	int (*is_partially_uptodate) (struct page *, read_descriptor_t *,
615 					unsigned long);
616 	int (*error_remove_page)(struct address_space *, struct page *);
617 };
618 
619 extern const struct address_space_operations empty_aops;
620 
621 /*
622  * pagecache_write_begin/pagecache_write_end must be used by general code
623  * to write into the pagecache.
624  */
625 int pagecache_write_begin(struct file *, struct address_space *mapping,
626 				loff_t pos, unsigned len, unsigned flags,
627 				struct page **pagep, void **fsdata);
628 
629 int pagecache_write_end(struct file *, struct address_space *mapping,
630 				loff_t pos, unsigned len, unsigned copied,
631 				struct page *page, void *fsdata);
632 
633 struct backing_dev_info;
634 struct address_space {
635 	struct inode		*host;		/* owner: inode, block_device */
636 	struct radix_tree_root	page_tree;	/* radix tree of all pages */
637 	spinlock_t		tree_lock;	/* and lock protecting it */
638 	unsigned int		i_mmap_writable;/* count VM_SHARED mappings */
639 	struct prio_tree_root	i_mmap;		/* tree of private and shared mappings */
640 	struct list_head	i_mmap_nonlinear;/*list VM_NONLINEAR mappings */
641 	struct mutex		i_mmap_mutex;	/* protect tree, count, list */
642 	/* Protected by tree_lock together with the radix tree */
643 	unsigned long		nrpages;	/* number of total pages */
644 	pgoff_t			writeback_index;/* writeback starts here */
645 	const struct address_space_operations *a_ops;	/* methods */
646 	unsigned long		flags;		/* error bits/gfp mask */
647 	struct backing_dev_info *backing_dev_info; /* device readahead, etc */
648 	spinlock_t		private_lock;	/* for use by the address_space */
649 	struct list_head	private_list;	/* ditto */
650 	struct address_space	*assoc_mapping;	/* ditto */
651 } __attribute__((aligned(sizeof(long))));
652 	/*
653 	 * On most architectures that alignment is already the case; but
654 	 * must be enforced here for CRIS, to let the least significant bit
655 	 * of struct page's "mapping" pointer be used for PAGE_MAPPING_ANON.
656 	 */
657 
658 struct block_device {
659 	dev_t			bd_dev;  /* not a kdev_t - it's a search key */
660 	int			bd_openers;
661 	struct inode *		bd_inode;	/* will die */
662 	struct super_block *	bd_super;
663 	struct mutex		bd_mutex;	/* open/close mutex */
664 	struct list_head	bd_inodes;
665 	void *			bd_claiming;
666 	void *			bd_holder;
667 	int			bd_holders;
668 	bool			bd_write_holder;
669 #ifdef CONFIG_SYSFS
670 	struct list_head	bd_holder_disks;
671 #endif
672 	struct block_device *	bd_contains;
673 	unsigned		bd_block_size;
674 	struct hd_struct *	bd_part;
675 	/* number of times partitions within this device have been opened. */
676 	unsigned		bd_part_count;
677 	int			bd_invalidated;
678 	struct gendisk *	bd_disk;
679 	struct list_head	bd_list;
680 	/*
681 	 * Private data.  You must have bd_claim'ed the block_device
682 	 * to use this.  NOTE:  bd_claim allows an owner to claim
683 	 * the same device multiple times, the owner must take special
684 	 * care to not mess up bd_private for that case.
685 	 */
686 	unsigned long		bd_private;
687 
688 	/* The counter of freeze processes */
689 	int			bd_fsfreeze_count;
690 	/* Mutex for freeze */
691 	struct mutex		bd_fsfreeze_mutex;
692 };
693 
694 /*
695  * Radix-tree tags, for tagging dirty and writeback pages within the pagecache
696  * radix trees
697  */
698 #define PAGECACHE_TAG_DIRTY	0
699 #define PAGECACHE_TAG_WRITEBACK	1
700 #define PAGECACHE_TAG_TOWRITE	2
701 
702 int mapping_tagged(struct address_space *mapping, int tag);
703 
704 /*
705  * Might pages of this file be mapped into userspace?
706  */
mapping_mapped(struct address_space * mapping)707 static inline int mapping_mapped(struct address_space *mapping)
708 {
709 	return	!prio_tree_empty(&mapping->i_mmap) ||
710 		!list_empty(&mapping->i_mmap_nonlinear);
711 }
712 
713 /*
714  * Might pages of this file have been modified in userspace?
715  * Note that i_mmap_writable counts all VM_SHARED vmas: do_mmap_pgoff
716  * marks vma as VM_SHARED if it is shared, and the file was opened for
717  * writing i.e. vma may be mprotected writable even if now readonly.
718  */
mapping_writably_mapped(struct address_space * mapping)719 static inline int mapping_writably_mapped(struct address_space *mapping)
720 {
721 	return mapping->i_mmap_writable != 0;
722 }
723 
724 /*
725  * Use sequence counter to get consistent i_size on 32-bit processors.
726  */
727 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
728 #include <linux/seqlock.h>
729 #define __NEED_I_SIZE_ORDERED
730 #define i_size_ordered_init(inode) seqcount_init(&inode->i_size_seqcount)
731 #else
732 #define i_size_ordered_init(inode) do { } while (0)
733 #endif
734 
735 struct posix_acl;
736 #define ACL_NOT_CACHED ((void *)(-1))
737 
738 struct inode {
739 	/* RCU path lookup touches following: */
740 	umode_t			i_mode;
741 	uid_t			i_uid;
742 	gid_t			i_gid;
743 	const struct inode_operations	*i_op;
744 	struct super_block	*i_sb;
745 
746 	spinlock_t		i_lock;	/* i_blocks, i_bytes, maybe i_size */
747 	unsigned int		i_flags;
748 	unsigned long		i_state;
749 #ifdef CONFIG_SECURITY
750 	void			*i_security;
751 #endif
752 	struct mutex		i_mutex;
753 
754 
755 	unsigned long		dirtied_when;	/* jiffies of first dirtying */
756 
757 	struct hlist_node	i_hash;
758 	struct list_head	i_wb_list;	/* backing dev IO list */
759 	struct list_head	i_lru;		/* inode LRU list */
760 	struct list_head	i_sb_list;
761 	union {
762 		struct list_head	i_dentry;
763 		struct rcu_head		i_rcu;
764 	};
765 	unsigned long		i_ino;
766 	atomic_t		i_count;
767 	unsigned int		i_nlink;
768 	dev_t			i_rdev;
769 	unsigned int		i_blkbits;
770 	u64			i_version;
771 	loff_t			i_size;
772 #ifdef __NEED_I_SIZE_ORDERED
773 	seqcount_t		i_size_seqcount;
774 #endif
775 	struct timespec		i_atime;
776 	struct timespec		i_mtime;
777 	struct timespec		i_ctime;
778 	blkcnt_t		i_blocks;
779 	unsigned short          i_bytes;
780 	struct rw_semaphore	i_alloc_sem;
781 	const struct file_operations	*i_fop;	/* former ->i_op->default_file_ops */
782 	struct file_lock	*i_flock;
783 	struct address_space	*i_mapping;
784 	struct address_space	i_data;
785 #ifdef CONFIG_QUOTA
786 	struct dquot		*i_dquot[MAXQUOTAS];
787 #endif
788 	struct list_head	i_devices;
789 	union {
790 		struct pipe_inode_info	*i_pipe;
791 		struct block_device	*i_bdev;
792 		struct cdev		*i_cdev;
793 	};
794 
795 	__u32			i_generation;
796 
797 #ifdef CONFIG_FSNOTIFY
798 	__u32			i_fsnotify_mask; /* all events this inode cares about */
799 	struct hlist_head	i_fsnotify_marks;
800 #endif
801 
802 #ifdef CONFIG_IMA
803 	atomic_t		i_readcount; /* struct files open RO */
804 #endif
805 	atomic_t		i_writecount;
806 #ifdef CONFIG_FS_POSIX_ACL
807 	struct posix_acl	*i_acl;
808 	struct posix_acl	*i_default_acl;
809 #endif
810 	void			*i_private; /* fs or device private pointer */
811 };
812 
inode_unhashed(struct inode * inode)813 static inline int inode_unhashed(struct inode *inode)
814 {
815 	return hlist_unhashed(&inode->i_hash);
816 }
817 
818 /*
819  * inode->i_mutex nesting subclasses for the lock validator:
820  *
821  * 0: the object of the current VFS operation
822  * 1: parent
823  * 2: child/target
824  * 3: quota file
825  *
826  * The locking order between these classes is
827  * parent -> child -> normal -> xattr -> quota
828  */
829 enum inode_i_mutex_lock_class
830 {
831 	I_MUTEX_NORMAL,
832 	I_MUTEX_PARENT,
833 	I_MUTEX_CHILD,
834 	I_MUTEX_XATTR,
835 	I_MUTEX_QUOTA
836 };
837 
838 /*
839  * NOTE: in a 32bit arch with a preemptable kernel and
840  * an UP compile the i_size_read/write must be atomic
841  * with respect to the local cpu (unlike with preempt disabled),
842  * but they don't need to be atomic with respect to other cpus like in
843  * true SMP (so they need either to either locally disable irq around
844  * the read or for example on x86 they can be still implemented as a
845  * cmpxchg8b without the need of the lock prefix). For SMP compiles
846  * and 64bit archs it makes no difference if preempt is enabled or not.
847  */
i_size_read(const struct inode * inode)848 static inline loff_t i_size_read(const struct inode *inode)
849 {
850 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
851 	loff_t i_size;
852 	unsigned int seq;
853 
854 	do {
855 		seq = read_seqcount_begin(&inode->i_size_seqcount);
856 		i_size = inode->i_size;
857 	} while (read_seqcount_retry(&inode->i_size_seqcount, seq));
858 	return i_size;
859 #elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT)
860 	loff_t i_size;
861 
862 	preempt_disable();
863 	i_size = inode->i_size;
864 	preempt_enable();
865 	return i_size;
866 #else
867 	return inode->i_size;
868 #endif
869 }
870 
871 /*
872  * NOTE: unlike i_size_read(), i_size_write() does need locking around it
873  * (normally i_mutex), otherwise on 32bit/SMP an update of i_size_seqcount
874  * can be lost, resulting in subsequent i_size_read() calls spinning forever.
875  */
i_size_write(struct inode * inode,loff_t i_size)876 static inline void i_size_write(struct inode *inode, loff_t i_size)
877 {
878 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
879 	write_seqcount_begin(&inode->i_size_seqcount);
880 	inode->i_size = i_size;
881 	write_seqcount_end(&inode->i_size_seqcount);
882 #elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT)
883 	preempt_disable();
884 	inode->i_size = i_size;
885 	preempt_enable();
886 #else
887 	inode->i_size = i_size;
888 #endif
889 }
890 
iminor(const struct inode * inode)891 static inline unsigned iminor(const struct inode *inode)
892 {
893 	return MINOR(inode->i_rdev);
894 }
895 
imajor(const struct inode * inode)896 static inline unsigned imajor(const struct inode *inode)
897 {
898 	return MAJOR(inode->i_rdev);
899 }
900 
901 extern struct block_device *I_BDEV(struct inode *inode);
902 
903 struct fown_struct {
904 	rwlock_t lock;          /* protects pid, uid, euid fields */
905 	struct pid *pid;	/* pid or -pgrp where SIGIO should be sent */
906 	enum pid_type pid_type;	/* Kind of process group SIGIO should be sent to */
907 	uid_t uid, euid;	/* uid/euid of process setting the owner */
908 	int signum;		/* posix.1b rt signal to be delivered on IO */
909 };
910 
911 /*
912  * Track a single file's readahead state
913  */
914 struct file_ra_state {
915 	pgoff_t start;			/* where readahead started */
916 	unsigned int size;		/* # of readahead pages */
917 	unsigned int async_size;	/* do asynchronous readahead when
918 					   there are only # of pages ahead */
919 
920 	unsigned int ra_pages;		/* Maximum readahead window */
921 	unsigned int mmap_miss;		/* Cache miss stat for mmap accesses */
922 	loff_t prev_pos;		/* Cache last read() position */
923 };
924 
925 /*
926  * Check if @index falls in the readahead windows.
927  */
ra_has_index(struct file_ra_state * ra,pgoff_t index)928 static inline int ra_has_index(struct file_ra_state *ra, pgoff_t index)
929 {
930 	return (index >= ra->start &&
931 		index <  ra->start + ra->size);
932 }
933 
934 #define FILE_MNT_WRITE_TAKEN	1
935 #define FILE_MNT_WRITE_RELEASED	2
936 
937 struct file {
938 	/*
939 	 * fu_list becomes invalid after file_free is called and queued via
940 	 * fu_rcuhead for RCU freeing
941 	 */
942 	union {
943 		struct list_head	fu_list;
944 		struct rcu_head 	fu_rcuhead;
945 	} f_u;
946 	struct path		f_path;
947 #define f_dentry	f_path.dentry
948 #define f_vfsmnt	f_path.mnt
949 	const struct file_operations	*f_op;
950 	spinlock_t		f_lock;  /* f_ep_links, f_flags, no IRQ */
951 #ifdef CONFIG_SMP
952 	int			f_sb_list_cpu;
953 #endif
954 	atomic_long_t		f_count;
955 	unsigned int 		f_flags;
956 	fmode_t			f_mode;
957 	loff_t			f_pos;
958 	struct fown_struct	f_owner;
959 	const struct cred	*f_cred;
960 	struct file_ra_state	f_ra;
961 
962 	u64			f_version;
963 #ifdef CONFIG_SECURITY
964 	void			*f_security;
965 #endif
966 	/* needed for tty driver, and maybe others */
967 	void			*private_data;
968 
969 #ifdef CONFIG_EPOLL
970 	/* Used by fs/eventpoll.c to link all the hooks to this file */
971 	struct list_head	f_ep_links;
972 	struct list_head	f_tfile_llink;
973 #endif /* #ifdef CONFIG_EPOLL */
974 	struct address_space	*f_mapping;
975 #ifdef CONFIG_DEBUG_WRITECOUNT
976 	unsigned long f_mnt_write_state;
977 #endif
978 };
979 
980 struct file_handle {
981 	__u32 handle_bytes;
982 	int handle_type;
983 	/* file identifier */
984 	unsigned char f_handle[0];
985 };
986 
987 #define get_file(x)	atomic_long_inc(&(x)->f_count)
988 #define fput_atomic(x)	atomic_long_add_unless(&(x)->f_count, -1, 1)
989 #define file_count(x)	atomic_long_read(&(x)->f_count)
990 
991 #ifdef CONFIG_DEBUG_WRITECOUNT
file_take_write(struct file * f)992 static inline void file_take_write(struct file *f)
993 {
994 	WARN_ON(f->f_mnt_write_state != 0);
995 	f->f_mnt_write_state = FILE_MNT_WRITE_TAKEN;
996 }
file_release_write(struct file * f)997 static inline void file_release_write(struct file *f)
998 {
999 	f->f_mnt_write_state |= FILE_MNT_WRITE_RELEASED;
1000 }
file_reset_write(struct file * f)1001 static inline void file_reset_write(struct file *f)
1002 {
1003 	f->f_mnt_write_state = 0;
1004 }
file_check_state(struct file * f)1005 static inline void file_check_state(struct file *f)
1006 {
1007 	/*
1008 	 * At this point, either both or neither of these bits
1009 	 * should be set.
1010 	 */
1011 	WARN_ON(f->f_mnt_write_state == FILE_MNT_WRITE_TAKEN);
1012 	WARN_ON(f->f_mnt_write_state == FILE_MNT_WRITE_RELEASED);
1013 }
file_check_writeable(struct file * f)1014 static inline int file_check_writeable(struct file *f)
1015 {
1016 	if (f->f_mnt_write_state == FILE_MNT_WRITE_TAKEN)
1017 		return 0;
1018 	printk(KERN_WARNING "writeable file with no "
1019 			    "mnt_want_write()\n");
1020 	WARN_ON(1);
1021 	return -EINVAL;
1022 }
1023 #else /* !CONFIG_DEBUG_WRITECOUNT */
file_take_write(struct file * filp)1024 static inline void file_take_write(struct file *filp) {}
file_release_write(struct file * filp)1025 static inline void file_release_write(struct file *filp) {}
file_reset_write(struct file * filp)1026 static inline void file_reset_write(struct file *filp) {}
file_check_state(struct file * filp)1027 static inline void file_check_state(struct file *filp) {}
file_check_writeable(struct file * filp)1028 static inline int file_check_writeable(struct file *filp)
1029 {
1030 	return 0;
1031 }
1032 #endif /* CONFIG_DEBUG_WRITECOUNT */
1033 
1034 #define	MAX_NON_LFS	((1UL<<31) - 1)
1035 
1036 /* Page cache limit. The filesystems should put that into their s_maxbytes
1037    limits, otherwise bad things can happen in VM. */
1038 #if BITS_PER_LONG==32
1039 #define MAX_LFS_FILESIZE	(((u64)PAGE_CACHE_SIZE << (BITS_PER_LONG-1))-1)
1040 #elif BITS_PER_LONG==64
1041 #define MAX_LFS_FILESIZE 	0x7fffffffffffffffUL
1042 #endif
1043 
1044 #define FL_POSIX	1
1045 #define FL_FLOCK	2
1046 #define FL_ACCESS	8	/* not trying to lock, just looking */
1047 #define FL_EXISTS	16	/* when unlocking, test for existence */
1048 #define FL_LEASE	32	/* lease held on this file */
1049 #define FL_CLOSE	64	/* unlock on close */
1050 #define FL_SLEEP	128	/* A blocking lock */
1051 
1052 /*
1053  * Special return value from posix_lock_file() and vfs_lock_file() for
1054  * asynchronous locking.
1055  */
1056 #define FILE_LOCK_DEFERRED 1
1057 
1058 /*
1059  * The POSIX file lock owner is determined by
1060  * the "struct files_struct" in the thread group
1061  * (or NULL for no owner - BSD locks).
1062  *
1063  * Lockd stuffs a "host" pointer into this.
1064  */
1065 typedef struct files_struct *fl_owner_t;
1066 
1067 struct file_lock_operations {
1068 	void (*fl_copy_lock)(struct file_lock *, struct file_lock *);
1069 	void (*fl_release_private)(struct file_lock *);
1070 };
1071 
1072 struct lock_manager_operations {
1073 	int (*fl_compare_owner)(struct file_lock *, struct file_lock *);
1074 	void (*fl_notify)(struct file_lock *);	/* unblock callback */
1075 	int (*fl_grant)(struct file_lock *, struct file_lock *, int);
1076 	void (*fl_release_private)(struct file_lock *);
1077 	void (*fl_break)(struct file_lock *);
1078 	int (*fl_change)(struct file_lock **, int);
1079 };
1080 
1081 struct lock_manager {
1082 	struct list_head list;
1083 };
1084 
1085 void locks_start_grace(struct lock_manager *);
1086 void locks_end_grace(struct lock_manager *);
1087 int locks_in_grace(void);
1088 
1089 /* that will die - we need it for nfs_lock_info */
1090 #include <linux/nfs_fs_i.h>
1091 
1092 struct file_lock {
1093 	struct file_lock *fl_next;	/* singly linked list for this inode  */
1094 	struct list_head fl_link;	/* doubly linked list of all locks */
1095 	struct list_head fl_block;	/* circular list of blocked processes */
1096 	fl_owner_t fl_owner;
1097 	unsigned char fl_flags;
1098 	unsigned char fl_type;
1099 	unsigned int fl_pid;
1100 	struct pid *fl_nspid;
1101 	wait_queue_head_t fl_wait;
1102 	struct file *fl_file;
1103 	loff_t fl_start;
1104 	loff_t fl_end;
1105 
1106 	struct fasync_struct *	fl_fasync; /* for lease break notifications */
1107 	unsigned long fl_break_time;	/* for nonblocking lease breaks */
1108 
1109 	const struct file_lock_operations *fl_ops;	/* Callbacks for filesystems */
1110 	const struct lock_manager_operations *fl_lmops;	/* Callbacks for lockmanagers */
1111 	union {
1112 		struct nfs_lock_info	nfs_fl;
1113 		struct nfs4_lock_info	nfs4_fl;
1114 		struct {
1115 			struct list_head link;	/* link in AFS vnode's pending_locks list */
1116 			int state;		/* state of grant or error if -ve */
1117 		} afs;
1118 	} fl_u;
1119 };
1120 
1121 /* The following constant reflects the upper bound of the file/locking space */
1122 #ifndef OFFSET_MAX
1123 #define INT_LIMIT(x)	(~((x)1 << (sizeof(x)*8 - 1)))
1124 #define OFFSET_MAX	INT_LIMIT(loff_t)
1125 #define OFFT_OFFSET_MAX	INT_LIMIT(off_t)
1126 #endif
1127 
1128 #include <linux/fcntl.h>
1129 
1130 extern void send_sigio(struct fown_struct *fown, int fd, int band);
1131 
1132 #ifdef CONFIG_FILE_LOCKING
1133 extern int fcntl_getlk(struct file *, struct flock __user *);
1134 extern int fcntl_setlk(unsigned int, struct file *, unsigned int,
1135 			struct flock __user *);
1136 
1137 #if BITS_PER_LONG == 32
1138 extern int fcntl_getlk64(struct file *, struct flock64 __user *);
1139 extern int fcntl_setlk64(unsigned int, struct file *, unsigned int,
1140 			struct flock64 __user *);
1141 #endif
1142 
1143 extern int fcntl_setlease(unsigned int fd, struct file *filp, long arg);
1144 extern int fcntl_getlease(struct file *filp);
1145 
1146 /* fs/locks.c */
1147 void locks_free_lock(struct file_lock *fl);
1148 extern void locks_init_lock(struct file_lock *);
1149 extern struct file_lock * locks_alloc_lock(void);
1150 extern void locks_copy_lock(struct file_lock *, struct file_lock *);
1151 extern void __locks_copy_lock(struct file_lock *, const struct file_lock *);
1152 extern void locks_remove_posix(struct file *, fl_owner_t);
1153 extern void locks_remove_flock(struct file *);
1154 extern void locks_release_private(struct file_lock *);
1155 extern void posix_test_lock(struct file *, struct file_lock *);
1156 extern int posix_lock_file(struct file *, struct file_lock *, struct file_lock *);
1157 extern int posix_lock_file_wait(struct file *, struct file_lock *);
1158 extern int posix_unblock_lock(struct file *, struct file_lock *);
1159 extern int vfs_test_lock(struct file *, struct file_lock *);
1160 extern int vfs_lock_file(struct file *, unsigned int, struct file_lock *, struct file_lock *);
1161 extern int vfs_cancel_lock(struct file *filp, struct file_lock *fl);
1162 extern int flock_lock_file_wait(struct file *filp, struct file_lock *fl);
1163 extern int __break_lease(struct inode *inode, unsigned int flags);
1164 extern void lease_get_mtime(struct inode *, struct timespec *time);
1165 extern int generic_setlease(struct file *, long, struct file_lock **);
1166 extern int vfs_setlease(struct file *, long, struct file_lock **);
1167 extern int lease_modify(struct file_lock **, int);
1168 extern int lock_may_read(struct inode *, loff_t start, unsigned long count);
1169 extern int lock_may_write(struct inode *, loff_t start, unsigned long count);
1170 extern void lock_flocks(void);
1171 extern void unlock_flocks(void);
1172 #else /* !CONFIG_FILE_LOCKING */
fcntl_getlk(struct file * file,struct flock __user * user)1173 static inline int fcntl_getlk(struct file *file, struct flock __user *user)
1174 {
1175 	return -EINVAL;
1176 }
1177 
fcntl_setlk(unsigned int fd,struct file * file,unsigned int cmd,struct flock __user * user)1178 static inline int fcntl_setlk(unsigned int fd, struct file *file,
1179 			      unsigned int cmd, struct flock __user *user)
1180 {
1181 	return -EACCES;
1182 }
1183 
1184 #if BITS_PER_LONG == 32
fcntl_getlk64(struct file * file,struct flock64 __user * user)1185 static inline int fcntl_getlk64(struct file *file, struct flock64 __user *user)
1186 {
1187 	return -EINVAL;
1188 }
1189 
fcntl_setlk64(unsigned int fd,struct file * file,unsigned int cmd,struct flock64 __user * user)1190 static inline int fcntl_setlk64(unsigned int fd, struct file *file,
1191 				unsigned int cmd, struct flock64 __user *user)
1192 {
1193 	return -EACCES;
1194 }
1195 #endif
fcntl_setlease(unsigned int fd,struct file * filp,long arg)1196 static inline int fcntl_setlease(unsigned int fd, struct file *filp, long arg)
1197 {
1198 	return 0;
1199 }
1200 
fcntl_getlease(struct file * filp)1201 static inline int fcntl_getlease(struct file *filp)
1202 {
1203 	return 0;
1204 }
1205 
locks_init_lock(struct file_lock * fl)1206 static inline void locks_init_lock(struct file_lock *fl)
1207 {
1208 	return;
1209 }
1210 
__locks_copy_lock(struct file_lock * new,struct file_lock * fl)1211 static inline void __locks_copy_lock(struct file_lock *new, struct file_lock *fl)
1212 {
1213 	return;
1214 }
1215 
locks_copy_lock(struct file_lock * new,struct file_lock * fl)1216 static inline void locks_copy_lock(struct file_lock *new, struct file_lock *fl)
1217 {
1218 	return;
1219 }
1220 
locks_remove_posix(struct file * filp,fl_owner_t owner)1221 static inline void locks_remove_posix(struct file *filp, fl_owner_t owner)
1222 {
1223 	return;
1224 }
1225 
locks_remove_flock(struct file * filp)1226 static inline void locks_remove_flock(struct file *filp)
1227 {
1228 	return;
1229 }
1230 
posix_test_lock(struct file * filp,struct file_lock * fl)1231 static inline void posix_test_lock(struct file *filp, struct file_lock *fl)
1232 {
1233 	return;
1234 }
1235 
posix_lock_file(struct file * filp,struct file_lock * fl,struct file_lock * conflock)1236 static inline int posix_lock_file(struct file *filp, struct file_lock *fl,
1237 				  struct file_lock *conflock)
1238 {
1239 	return -ENOLCK;
1240 }
1241 
posix_lock_file_wait(struct file * filp,struct file_lock * fl)1242 static inline int posix_lock_file_wait(struct file *filp, struct file_lock *fl)
1243 {
1244 	return -ENOLCK;
1245 }
1246 
posix_unblock_lock(struct file * filp,struct file_lock * waiter)1247 static inline int posix_unblock_lock(struct file *filp,
1248 				     struct file_lock *waiter)
1249 {
1250 	return -ENOENT;
1251 }
1252 
vfs_test_lock(struct file * filp,struct file_lock * fl)1253 static inline int vfs_test_lock(struct file *filp, struct file_lock *fl)
1254 {
1255 	return 0;
1256 }
1257 
vfs_lock_file(struct file * filp,unsigned int cmd,struct file_lock * fl,struct file_lock * conf)1258 static inline int vfs_lock_file(struct file *filp, unsigned int cmd,
1259 				struct file_lock *fl, struct file_lock *conf)
1260 {
1261 	return -ENOLCK;
1262 }
1263 
vfs_cancel_lock(struct file * filp,struct file_lock * fl)1264 static inline int vfs_cancel_lock(struct file *filp, struct file_lock *fl)
1265 {
1266 	return 0;
1267 }
1268 
flock_lock_file_wait(struct file * filp,struct file_lock * request)1269 static inline int flock_lock_file_wait(struct file *filp,
1270 				       struct file_lock *request)
1271 {
1272 	return -ENOLCK;
1273 }
1274 
__break_lease(struct inode * inode,unsigned int mode)1275 static inline int __break_lease(struct inode *inode, unsigned int mode)
1276 {
1277 	return 0;
1278 }
1279 
lease_get_mtime(struct inode * inode,struct timespec * time)1280 static inline void lease_get_mtime(struct inode *inode, struct timespec *time)
1281 {
1282 	return;
1283 }
1284 
generic_setlease(struct file * filp,long arg,struct file_lock ** flp)1285 static inline int generic_setlease(struct file *filp, long arg,
1286 				    struct file_lock **flp)
1287 {
1288 	return -EINVAL;
1289 }
1290 
vfs_setlease(struct file * filp,long arg,struct file_lock ** lease)1291 static inline int vfs_setlease(struct file *filp, long arg,
1292 			       struct file_lock **lease)
1293 {
1294 	return -EINVAL;
1295 }
1296 
lease_modify(struct file_lock ** before,int arg)1297 static inline int lease_modify(struct file_lock **before, int arg)
1298 {
1299 	return -EINVAL;
1300 }
1301 
lock_may_read(struct inode * inode,loff_t start,unsigned long len)1302 static inline int lock_may_read(struct inode *inode, loff_t start,
1303 				unsigned long len)
1304 {
1305 	return 1;
1306 }
1307 
lock_may_write(struct inode * inode,loff_t start,unsigned long len)1308 static inline int lock_may_write(struct inode *inode, loff_t start,
1309 				 unsigned long len)
1310 {
1311 	return 1;
1312 }
1313 
lock_flocks(void)1314 static inline void lock_flocks(void)
1315 {
1316 }
1317 
unlock_flocks(void)1318 static inline void unlock_flocks(void)
1319 {
1320 }
1321 
1322 #endif /* !CONFIG_FILE_LOCKING */
1323 
1324 
1325 struct fasync_struct {
1326 	spinlock_t		fa_lock;
1327 	int			magic;
1328 	int			fa_fd;
1329 	struct fasync_struct	*fa_next; /* singly linked list */
1330 	struct file		*fa_file;
1331 	struct rcu_head		fa_rcu;
1332 };
1333 
1334 #define FASYNC_MAGIC 0x4601
1335 
1336 /* SMP safe fasync helpers: */
1337 extern int fasync_helper(int, struct file *, int, struct fasync_struct **);
1338 extern struct fasync_struct *fasync_insert_entry(int, struct file *, struct fasync_struct **, struct fasync_struct *);
1339 extern int fasync_remove_entry(struct file *, struct fasync_struct **);
1340 extern struct fasync_struct *fasync_alloc(void);
1341 extern void fasync_free(struct fasync_struct *);
1342 
1343 /* can be called from interrupts */
1344 extern void kill_fasync(struct fasync_struct **, int, int);
1345 
1346 extern int __f_setown(struct file *filp, struct pid *, enum pid_type, int force);
1347 extern int f_setown(struct file *filp, unsigned long arg, int force);
1348 extern void f_delown(struct file *filp);
1349 extern pid_t f_getown(struct file *filp);
1350 extern int send_sigurg(struct fown_struct *fown);
1351 
1352 /*
1353  *	Umount options
1354  */
1355 
1356 #define MNT_FORCE	0x00000001	/* Attempt to forcibily umount */
1357 #define MNT_DETACH	0x00000002	/* Just detach from the tree */
1358 #define MNT_EXPIRE	0x00000004	/* Mark for expiry */
1359 #define UMOUNT_NOFOLLOW	0x00000008	/* Don't follow symlink on umount */
1360 #define UMOUNT_UNUSED	0x80000000	/* Flag guaranteed to be unused */
1361 
1362 extern struct list_head super_blocks;
1363 extern spinlock_t sb_lock;
1364 
1365 struct super_block {
1366 	struct list_head	s_list;		/* Keep this first */
1367 	dev_t			s_dev;		/* search index; _not_ kdev_t */
1368 	unsigned char		s_dirt;
1369 	unsigned char		s_blocksize_bits;
1370 	unsigned long		s_blocksize;
1371 	loff_t			s_maxbytes;	/* Max file size */
1372 	struct file_system_type	*s_type;
1373 	const struct super_operations	*s_op;
1374 	const struct dquot_operations	*dq_op;
1375 	const struct quotactl_ops	*s_qcop;
1376 	const struct export_operations *s_export_op;
1377 	unsigned long		s_flags;
1378 	unsigned long		s_magic;
1379 	struct dentry		*s_root;
1380 	struct rw_semaphore	s_umount;
1381 	struct mutex		s_lock;
1382 	int			s_count;
1383 	atomic_t		s_active;
1384 #ifdef CONFIG_SECURITY
1385 	void                    *s_security;
1386 #endif
1387 	const struct xattr_handler **s_xattr;
1388 
1389 	struct list_head	s_inodes;	/* all inodes */
1390 	struct hlist_bl_head	s_anon;		/* anonymous dentries for (nfs) exporting */
1391 #ifdef CONFIG_SMP
1392 	struct list_head __percpu *s_files;
1393 #else
1394 	struct list_head	s_files;
1395 #endif
1396 	/* s_dentry_lru, s_nr_dentry_unused protected by dcache.c lru locks */
1397 	struct list_head	s_dentry_lru;	/* unused dentry lru */
1398 	int			s_nr_dentry_unused;	/* # of dentry on lru */
1399 
1400 	struct block_device	*s_bdev;
1401 	struct backing_dev_info *s_bdi;
1402 	struct mtd_info		*s_mtd;
1403 	struct list_head	s_instances;
1404 	struct quota_info	s_dquot;	/* Diskquota specific options */
1405 
1406 	int			s_frozen;
1407 	wait_queue_head_t	s_wait_unfrozen;
1408 
1409 	char s_id[32];				/* Informational name */
1410 	u8 s_uuid[16];				/* UUID */
1411 
1412 	void 			*s_fs_info;	/* Filesystem private info */
1413 	fmode_t			s_mode;
1414 
1415 	/* Granularity of c/m/atime in ns.
1416 	   Cannot be worse than a second */
1417 	u32		   s_time_gran;
1418 
1419 	/*
1420 	 * The next field is for VFS *only*. No filesystems have any business
1421 	 * even looking at it. You had been warned.
1422 	 */
1423 	struct mutex s_vfs_rename_mutex;	/* Kludge */
1424 
1425 	/*
1426 	 * Filesystem subtype.  If non-empty the filesystem type field
1427 	 * in /proc/mounts will be "type.subtype"
1428 	 */
1429 	char *s_subtype;
1430 
1431 	/*
1432 	 * Saved mount options for lazy filesystems using
1433 	 * generic_show_options()
1434 	 */
1435 	char __rcu *s_options;
1436 	const struct dentry_operations *s_d_op; /* default d_op for dentries */
1437 
1438 	/*
1439 	 * Saved pool identifier for cleancache (-1 means none)
1440 	 */
1441 	int cleancache_poolid;
1442 };
1443 
1444 extern struct timespec current_fs_time(struct super_block *sb);
1445 
1446 /*
1447  * Snapshotting support.
1448  */
1449 enum {
1450 	SB_UNFROZEN = 0,
1451 	SB_FREEZE_WRITE	= 1,
1452 	SB_FREEZE_TRANS = 2,
1453 };
1454 
1455 #define vfs_check_frozen(sb, level) \
1456 	wait_event((sb)->s_wait_unfrozen, ((sb)->s_frozen < (level)))
1457 
1458 #define get_fs_excl() atomic_inc(&current->fs_excl)
1459 #define put_fs_excl() atomic_dec(&current->fs_excl)
1460 #define has_fs_excl() atomic_read(&current->fs_excl)
1461 
1462 /*
1463  * until VFS tracks user namespaces for inodes, just make all files
1464  * belong to init_user_ns
1465  */
1466 extern struct user_namespace init_user_ns;
1467 #define inode_userns(inode) (&init_user_ns)
1468 extern bool inode_owner_or_capable(const struct inode *inode);
1469 
1470 /* not quite ready to be deprecated, but... */
1471 extern void lock_super(struct super_block *);
1472 extern void unlock_super(struct super_block *);
1473 
1474 /*
1475  * VFS helper functions..
1476  */
1477 extern int vfs_create(struct inode *, struct dentry *, int, struct nameidata *);
1478 extern int vfs_mkdir(struct inode *, struct dentry *, int);
1479 extern int vfs_mknod(struct inode *, struct dentry *, int, dev_t);
1480 extern int vfs_symlink(struct inode *, struct dentry *, const char *);
1481 extern int vfs_link(struct dentry *, struct inode *, struct dentry *);
1482 extern int vfs_rmdir(struct inode *, struct dentry *);
1483 extern int vfs_unlink(struct inode *, struct dentry *);
1484 extern int vfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *);
1485 
1486 /*
1487  * VFS dentry helper functions.
1488  */
1489 extern void dentry_unhash(struct dentry *dentry);
1490 
1491 /*
1492  * VFS file helper functions.
1493  */
1494 extern int file_permission(struct file *, int);
1495 extern void inode_init_owner(struct inode *inode, const struct inode *dir,
1496 			mode_t mode);
1497 /*
1498  * VFS FS_IOC_FIEMAP helper definitions.
1499  */
1500 struct fiemap_extent_info {
1501 	unsigned int fi_flags;		/* Flags as passed from user */
1502 	unsigned int fi_extents_mapped;	/* Number of mapped extents */
1503 	unsigned int fi_extents_max;	/* Size of fiemap_extent array */
1504 	struct fiemap_extent __user *fi_extents_start; /* Start of
1505 							fiemap_extent array */
1506 };
1507 int fiemap_fill_next_extent(struct fiemap_extent_info *info, u64 logical,
1508 			    u64 phys, u64 len, u32 flags);
1509 int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags);
1510 
1511 /*
1512  * File types
1513  *
1514  * NOTE! These match bits 12..15 of stat.st_mode
1515  * (ie "(i_mode >> 12) & 15").
1516  */
1517 #define DT_UNKNOWN	0
1518 #define DT_FIFO		1
1519 #define DT_CHR		2
1520 #define DT_DIR		4
1521 #define DT_BLK		6
1522 #define DT_REG		8
1523 #define DT_LNK		10
1524 #define DT_SOCK		12
1525 #define DT_WHT		14
1526 
1527 /*
1528  * This is the "filldir" function type, used by readdir() to let
1529  * the kernel specify what kind of dirent layout it wants to have.
1530  * This allows the kernel to read directories into kernel space or
1531  * to have different dirent layouts depending on the binary type.
1532  */
1533 typedef int (*filldir_t)(void *, const char *, int, loff_t, u64, unsigned);
1534 struct block_device_operations;
1535 
1536 /* These macros are for out of kernel modules to test that
1537  * the kernel supports the unlocked_ioctl and compat_ioctl
1538  * fields in struct file_operations. */
1539 #define HAVE_COMPAT_IOCTL 1
1540 #define HAVE_UNLOCKED_IOCTL 1
1541 
1542 /*
1543  * NOTE:
1544  * all file operations except setlease can be called without
1545  * the big kernel lock held in all filesystems.
1546  */
1547 struct file_operations {
1548 	struct module *owner;
1549 	loff_t (*llseek) (struct file *, loff_t, int);
1550 	ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
1551 	ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
1552 	ssize_t (*aio_read) (struct kiocb *, const struct iovec *, unsigned long, loff_t);
1553 	ssize_t (*aio_write) (struct kiocb *, const struct iovec *, unsigned long, loff_t);
1554 	int (*readdir) (struct file *, void *, filldir_t);
1555 	unsigned int (*poll) (struct file *, struct poll_table_struct *);
1556 	long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
1557 	long (*compat_ioctl) (struct file *, unsigned int, unsigned long);
1558 	int (*mmap) (struct file *, struct vm_area_struct *);
1559 	int (*open) (struct inode *, struct file *);
1560 	int (*flush) (struct file *, fl_owner_t id);
1561 	int (*release) (struct inode *, struct file *);
1562 	int (*fsync) (struct file *, int datasync);
1563 	int (*aio_fsync) (struct kiocb *, int datasync);
1564 	int (*fasync) (int, struct file *, int);
1565 	int (*lock) (struct file *, int, struct file_lock *);
1566 	ssize_t (*sendpage) (struct file *, struct page *, int, size_t, loff_t *, int);
1567 	unsigned long (*get_unmapped_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
1568 	int (*check_flags)(int);
1569 	int (*flock) (struct file *, int, struct file_lock *);
1570 	ssize_t (*splice_write)(struct pipe_inode_info *, struct file *, loff_t *, size_t, unsigned int);
1571 	ssize_t (*splice_read)(struct file *, loff_t *, struct pipe_inode_info *, size_t, unsigned int);
1572 	int (*setlease)(struct file *, long, struct file_lock **);
1573 	long (*fallocate)(struct file *file, int mode, loff_t offset,
1574 			  loff_t len);
1575 };
1576 
1577 #define IPERM_FLAG_RCU	0x0001
1578 
1579 struct inode_operations {
1580 	struct dentry * (*lookup) (struct inode *,struct dentry *, struct nameidata *);
1581 	void * (*follow_link) (struct dentry *, struct nameidata *);
1582 	int (*permission) (struct inode *, int, unsigned int);
1583 	int (*check_acl)(struct inode *, int, unsigned int);
1584 
1585 	int (*readlink) (struct dentry *, char __user *,int);
1586 	void (*put_link) (struct dentry *, struct nameidata *, void *);
1587 
1588 	int (*create) (struct inode *,struct dentry *,int, struct nameidata *);
1589 	int (*link) (struct dentry *,struct inode *,struct dentry *);
1590 	int (*unlink) (struct inode *,struct dentry *);
1591 	int (*symlink) (struct inode *,struct dentry *,const char *);
1592 	int (*mkdir) (struct inode *,struct dentry *,int);
1593 	int (*rmdir) (struct inode *,struct dentry *);
1594 	int (*mknod) (struct inode *,struct dentry *,int,dev_t);
1595 	int (*rename) (struct inode *, struct dentry *,
1596 			struct inode *, struct dentry *);
1597 	void (*truncate) (struct inode *);
1598 	int (*setattr) (struct dentry *, struct iattr *);
1599 	int (*getattr) (struct vfsmount *mnt, struct dentry *, struct kstat *);
1600 	int (*setxattr) (struct dentry *, const char *,const void *,size_t,int);
1601 	ssize_t (*getxattr) (struct dentry *, const char *, void *, size_t);
1602 	ssize_t (*listxattr) (struct dentry *, char *, size_t);
1603 	int (*removexattr) (struct dentry *, const char *);
1604 	void (*truncate_range)(struct inode *, loff_t, loff_t);
1605 	int (*fiemap)(struct inode *, struct fiemap_extent_info *, u64 start,
1606 		      u64 len);
1607 } ____cacheline_aligned;
1608 
1609 struct seq_file;
1610 
1611 ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector,
1612 				unsigned long nr_segs, unsigned long fast_segs,
1613 				struct iovec *fast_pointer,
1614 				struct iovec **ret_pointer);
1615 
1616 extern ssize_t vfs_read(struct file *, char __user *, size_t, loff_t *);
1617 extern ssize_t vfs_write(struct file *, const char __user *, size_t, loff_t *);
1618 extern ssize_t vfs_readv(struct file *, const struct iovec __user *,
1619 		unsigned long, loff_t *);
1620 extern ssize_t vfs_writev(struct file *, const struct iovec __user *,
1621 		unsigned long, loff_t *);
1622 
1623 struct super_operations {
1624    	struct inode *(*alloc_inode)(struct super_block *sb);
1625 	void (*destroy_inode)(struct inode *);
1626 
1627    	void (*dirty_inode) (struct inode *, int flags);
1628 	int (*write_inode) (struct inode *, struct writeback_control *wbc);
1629 	int (*drop_inode) (struct inode *);
1630 	void (*evict_inode) (struct inode *);
1631 	void (*put_super) (struct super_block *);
1632 	void (*write_super) (struct super_block *);
1633 	int (*sync_fs)(struct super_block *sb, int wait);
1634 	int (*freeze_fs) (struct super_block *);
1635 	int (*unfreeze_fs) (struct super_block *);
1636 	int (*statfs) (struct dentry *, struct kstatfs *);
1637 	int (*remount_fs) (struct super_block *, int *, char *);
1638 	void (*umount_begin) (struct super_block *);
1639 
1640 	int (*show_options)(struct seq_file *, struct vfsmount *);
1641 	int (*show_devname)(struct seq_file *, struct vfsmount *);
1642 	int (*show_path)(struct seq_file *, struct vfsmount *);
1643 	int (*show_stats)(struct seq_file *, struct vfsmount *);
1644 #ifdef CONFIG_QUOTA
1645 	ssize_t (*quota_read)(struct super_block *, int, char *, size_t, loff_t);
1646 	ssize_t (*quota_write)(struct super_block *, int, const char *, size_t, loff_t);
1647 #endif
1648 	int (*bdev_try_to_free_page)(struct super_block*, struct page*, gfp_t);
1649 };
1650 
1651 /*
1652  * Inode state bits.  Protected by inode->i_lock
1653  *
1654  * Three bits determine the dirty state of the inode, I_DIRTY_SYNC,
1655  * I_DIRTY_DATASYNC and I_DIRTY_PAGES.
1656  *
1657  * Four bits define the lifetime of an inode.  Initially, inodes are I_NEW,
1658  * until that flag is cleared.  I_WILL_FREE, I_FREEING and I_CLEAR are set at
1659  * various stages of removing an inode.
1660  *
1661  * Two bits are used for locking and completion notification, I_NEW and I_SYNC.
1662  *
1663  * I_DIRTY_SYNC		Inode is dirty, but doesn't have to be written on
1664  *			fdatasync().  i_atime is the usual cause.
1665  * I_DIRTY_DATASYNC	Data-related inode changes pending. We keep track of
1666  *			these changes separately from I_DIRTY_SYNC so that we
1667  *			don't have to write inode on fdatasync() when only
1668  *			mtime has changed in it.
1669  * I_DIRTY_PAGES	Inode has dirty pages.  Inode itself may be clean.
1670  * I_NEW		Serves as both a mutex and completion notification.
1671  *			New inodes set I_NEW.  If two processes both create
1672  *			the same inode, one of them will release its inode and
1673  *			wait for I_NEW to be released before returning.
1674  *			Inodes in I_WILL_FREE, I_FREEING or I_CLEAR state can
1675  *			also cause waiting on I_NEW, without I_NEW actually
1676  *			being set.  find_inode() uses this to prevent returning
1677  *			nearly-dead inodes.
1678  * I_WILL_FREE		Must be set when calling write_inode_now() if i_count
1679  *			is zero.  I_FREEING must be set when I_WILL_FREE is
1680  *			cleared.
1681  * I_FREEING		Set when inode is about to be freed but still has dirty
1682  *			pages or buffers attached or the inode itself is still
1683  *			dirty.
1684  * I_CLEAR		Added by end_writeback().  In this state the inode is clean
1685  *			and can be destroyed.  Inode keeps I_FREEING.
1686  *
1687  *			Inodes that are I_WILL_FREE, I_FREEING or I_CLEAR are
1688  *			prohibited for many purposes.  iget() must wait for
1689  *			the inode to be completely released, then create it
1690  *			anew.  Other functions will just ignore such inodes,
1691  *			if appropriate.  I_NEW is used for waiting.
1692  *
1693  * I_SYNC		Synchonized write of dirty inode data.  The bits is
1694  *			set during data writeback, and cleared with a wakeup
1695  *			on the bit address once it is done.
1696  *
1697  * Q: What is the difference between I_WILL_FREE and I_FREEING?
1698  */
1699 #define I_DIRTY_SYNC		(1 << 0)
1700 #define I_DIRTY_DATASYNC	(1 << 1)
1701 #define I_DIRTY_PAGES		(1 << 2)
1702 #define __I_NEW			3
1703 #define I_NEW			(1 << __I_NEW)
1704 #define I_WILL_FREE		(1 << 4)
1705 #define I_FREEING		(1 << 5)
1706 #define I_CLEAR			(1 << 6)
1707 #define __I_SYNC		7
1708 #define I_SYNC			(1 << __I_SYNC)
1709 #define I_REFERENCED		(1 << 8)
1710 
1711 #define I_DIRTY (I_DIRTY_SYNC | I_DIRTY_DATASYNC | I_DIRTY_PAGES)
1712 
1713 extern void __mark_inode_dirty(struct inode *, int);
mark_inode_dirty(struct inode * inode)1714 static inline void mark_inode_dirty(struct inode *inode)
1715 {
1716 	__mark_inode_dirty(inode, I_DIRTY);
1717 }
1718 
mark_inode_dirty_sync(struct inode * inode)1719 static inline void mark_inode_dirty_sync(struct inode *inode)
1720 {
1721 	__mark_inode_dirty(inode, I_DIRTY_SYNC);
1722 }
1723 
1724 /**
1725  * inc_nlink - directly increment an inode's link count
1726  * @inode: inode
1727  *
1728  * This is a low-level filesystem helper to replace any
1729  * direct filesystem manipulation of i_nlink.  Currently,
1730  * it is only here for parity with dec_nlink().
1731  */
inc_nlink(struct inode * inode)1732 static inline void inc_nlink(struct inode *inode)
1733 {
1734 	inode->i_nlink++;
1735 }
1736 
inode_inc_link_count(struct inode * inode)1737 static inline void inode_inc_link_count(struct inode *inode)
1738 {
1739 	inc_nlink(inode);
1740 	mark_inode_dirty(inode);
1741 }
1742 
1743 /**
1744  * drop_nlink - directly drop an inode's link count
1745  * @inode: inode
1746  *
1747  * This is a low-level filesystem helper to replace any
1748  * direct filesystem manipulation of i_nlink.  In cases
1749  * where we are attempting to track writes to the
1750  * filesystem, a decrement to zero means an imminent
1751  * write when the file is truncated and actually unlinked
1752  * on the filesystem.
1753  */
drop_nlink(struct inode * inode)1754 static inline void drop_nlink(struct inode *inode)
1755 {
1756 	inode->i_nlink--;
1757 }
1758 
1759 /**
1760  * clear_nlink - directly zero an inode's link count
1761  * @inode: inode
1762  *
1763  * This is a low-level filesystem helper to replace any
1764  * direct filesystem manipulation of i_nlink.  See
1765  * drop_nlink() for why we care about i_nlink hitting zero.
1766  */
clear_nlink(struct inode * inode)1767 static inline void clear_nlink(struct inode *inode)
1768 {
1769 	inode->i_nlink = 0;
1770 }
1771 
inode_dec_link_count(struct inode * inode)1772 static inline void inode_dec_link_count(struct inode *inode)
1773 {
1774 	drop_nlink(inode);
1775 	mark_inode_dirty(inode);
1776 }
1777 
1778 /**
1779  * inode_inc_iversion - increments i_version
1780  * @inode: inode that need to be updated
1781  *
1782  * Every time the inode is modified, the i_version field will be incremented.
1783  * The filesystem has to be mounted with i_version flag
1784  */
1785 
inode_inc_iversion(struct inode * inode)1786 static inline void inode_inc_iversion(struct inode *inode)
1787 {
1788        spin_lock(&inode->i_lock);
1789        inode->i_version++;
1790        spin_unlock(&inode->i_lock);
1791 }
1792 
1793 extern void touch_atime(struct vfsmount *mnt, struct dentry *dentry);
file_accessed(struct file * file)1794 static inline void file_accessed(struct file *file)
1795 {
1796 	if (!(file->f_flags & O_NOATIME))
1797 		touch_atime(file->f_path.mnt, file->f_path.dentry);
1798 }
1799 
1800 int sync_inode(struct inode *inode, struct writeback_control *wbc);
1801 int sync_inode_metadata(struct inode *inode, int wait);
1802 
1803 struct file_system_type {
1804 	const char *name;
1805 	int fs_flags;
1806 	struct dentry *(*mount) (struct file_system_type *, int,
1807 		       const char *, void *);
1808 	void (*kill_sb) (struct super_block *);
1809 	struct module *owner;
1810 	struct file_system_type * next;
1811 	struct list_head fs_supers;
1812 
1813 	struct lock_class_key s_lock_key;
1814 	struct lock_class_key s_umount_key;
1815 	struct lock_class_key s_vfs_rename_key;
1816 
1817 	struct lock_class_key i_lock_key;
1818 	struct lock_class_key i_mutex_key;
1819 	struct lock_class_key i_mutex_dir_key;
1820 	struct lock_class_key i_alloc_sem_key;
1821 };
1822 
1823 extern struct dentry *mount_ns(struct file_system_type *fs_type, int flags,
1824 	void *data, int (*fill_super)(struct super_block *, void *, int));
1825 extern struct dentry *mount_bdev(struct file_system_type *fs_type,
1826 	int flags, const char *dev_name, void *data,
1827 	int (*fill_super)(struct super_block *, void *, int));
1828 extern struct dentry *mount_single(struct file_system_type *fs_type,
1829 	int flags, void *data,
1830 	int (*fill_super)(struct super_block *, void *, int));
1831 extern struct dentry *mount_nodev(struct file_system_type *fs_type,
1832 	int flags, void *data,
1833 	int (*fill_super)(struct super_block *, void *, int));
1834 void generic_shutdown_super(struct super_block *sb);
1835 void kill_block_super(struct super_block *sb);
1836 void kill_anon_super(struct super_block *sb);
1837 void kill_litter_super(struct super_block *sb);
1838 void deactivate_super(struct super_block *sb);
1839 void deactivate_locked_super(struct super_block *sb);
1840 int set_anon_super(struct super_block *s, void *data);
1841 struct super_block *sget(struct file_system_type *type,
1842 			int (*test)(struct super_block *,void *),
1843 			int (*set)(struct super_block *,void *),
1844 			void *data);
1845 extern struct dentry *mount_pseudo(struct file_system_type *, char *,
1846 	const struct super_operations *ops,
1847 	const struct dentry_operations *dops,
1848 	unsigned long);
1849 
sb_mark_dirty(struct super_block * sb)1850 static inline void sb_mark_dirty(struct super_block *sb)
1851 {
1852 	sb->s_dirt = 1;
1853 }
sb_mark_clean(struct super_block * sb)1854 static inline void sb_mark_clean(struct super_block *sb)
1855 {
1856 	sb->s_dirt = 0;
1857 }
sb_is_dirty(struct super_block * sb)1858 static inline int sb_is_dirty(struct super_block *sb)
1859 {
1860 	return sb->s_dirt;
1861 }
1862 
1863 /* Alas, no aliases. Too much hassle with bringing module.h everywhere */
1864 #define fops_get(fops) \
1865 	(((fops) && try_module_get((fops)->owner) ? (fops) : NULL))
1866 #define fops_put(fops) \
1867 	do { if (fops) module_put((fops)->owner); } while(0)
1868 
1869 extern int register_filesystem(struct file_system_type *);
1870 extern int unregister_filesystem(struct file_system_type *);
1871 extern struct vfsmount *kern_mount_data(struct file_system_type *, void *data);
1872 #define kern_mount(type) kern_mount_data(type, NULL)
1873 extern int may_umount_tree(struct vfsmount *);
1874 extern int may_umount(struct vfsmount *);
1875 extern long do_mount(char *, char *, char *, unsigned long, void *);
1876 extern struct vfsmount *collect_mounts(struct path *);
1877 extern void drop_collected_mounts(struct vfsmount *);
1878 extern int iterate_mounts(int (*)(struct vfsmount *, void *), void *,
1879 			  struct vfsmount *);
1880 extern int vfs_statfs(struct path *, struct kstatfs *);
1881 extern int user_statfs(const char __user *, struct kstatfs *);
1882 extern int fd_statfs(int, struct kstatfs *);
1883 extern int statfs_by_dentry(struct dentry *, struct kstatfs *);
1884 extern int freeze_super(struct super_block *super);
1885 extern int thaw_super(struct super_block *super);
1886 extern bool our_mnt(struct vfsmount *mnt);
1887 
1888 extern int current_umask(void);
1889 
1890 /* /sys/fs */
1891 extern struct kobject *fs_kobj;
1892 
1893 #define MAX_RW_COUNT (INT_MAX & PAGE_CACHE_MASK)
1894 extern int rw_verify_area(int, struct file *, loff_t *, size_t);
1895 
1896 #define FLOCK_VERIFY_READ  1
1897 #define FLOCK_VERIFY_WRITE 2
1898 
1899 #ifdef CONFIG_FILE_LOCKING
1900 extern int locks_mandatory_locked(struct inode *);
1901 extern int locks_mandatory_area(int, struct inode *, struct file *, loff_t, size_t);
1902 
1903 /*
1904  * Candidates for mandatory locking have the setgid bit set
1905  * but no group execute bit -  an otherwise meaningless combination.
1906  */
1907 
__mandatory_lock(struct inode * ino)1908 static inline int __mandatory_lock(struct inode *ino)
1909 {
1910 	return (ino->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID;
1911 }
1912 
1913 /*
1914  * ... and these candidates should be on MS_MANDLOCK mounted fs,
1915  * otherwise these will be advisory locks
1916  */
1917 
mandatory_lock(struct inode * ino)1918 static inline int mandatory_lock(struct inode *ino)
1919 {
1920 	return IS_MANDLOCK(ino) && __mandatory_lock(ino);
1921 }
1922 
locks_verify_locked(struct inode * inode)1923 static inline int locks_verify_locked(struct inode *inode)
1924 {
1925 	if (mandatory_lock(inode))
1926 		return locks_mandatory_locked(inode);
1927 	return 0;
1928 }
1929 
locks_verify_truncate(struct inode * inode,struct file * filp,loff_t size)1930 static inline int locks_verify_truncate(struct inode *inode,
1931 				    struct file *filp,
1932 				    loff_t size)
1933 {
1934 	if (inode->i_flock && mandatory_lock(inode))
1935 		return locks_mandatory_area(
1936 			FLOCK_VERIFY_WRITE, inode, filp,
1937 			size < inode->i_size ? size : inode->i_size,
1938 			(size < inode->i_size ? inode->i_size - size
1939 			 : size - inode->i_size)
1940 		);
1941 	return 0;
1942 }
1943 
break_lease(struct inode * inode,unsigned int mode)1944 static inline int break_lease(struct inode *inode, unsigned int mode)
1945 {
1946 	if (inode->i_flock)
1947 		return __break_lease(inode, mode);
1948 	return 0;
1949 }
1950 #else /* !CONFIG_FILE_LOCKING */
locks_mandatory_locked(struct inode * inode)1951 static inline int locks_mandatory_locked(struct inode *inode)
1952 {
1953 	return 0;
1954 }
1955 
locks_mandatory_area(int rw,struct inode * inode,struct file * filp,loff_t offset,size_t count)1956 static inline int locks_mandatory_area(int rw, struct inode *inode,
1957 				       struct file *filp, loff_t offset,
1958 				       size_t count)
1959 {
1960 	return 0;
1961 }
1962 
__mandatory_lock(struct inode * inode)1963 static inline int __mandatory_lock(struct inode *inode)
1964 {
1965 	return 0;
1966 }
1967 
mandatory_lock(struct inode * inode)1968 static inline int mandatory_lock(struct inode *inode)
1969 {
1970 	return 0;
1971 }
1972 
locks_verify_locked(struct inode * inode)1973 static inline int locks_verify_locked(struct inode *inode)
1974 {
1975 	return 0;
1976 }
1977 
locks_verify_truncate(struct inode * inode,struct file * filp,size_t size)1978 static inline int locks_verify_truncate(struct inode *inode, struct file *filp,
1979 					size_t size)
1980 {
1981 	return 0;
1982 }
1983 
break_lease(struct inode * inode,unsigned int mode)1984 static inline int break_lease(struct inode *inode, unsigned int mode)
1985 {
1986 	return 0;
1987 }
1988 
1989 #endif /* CONFIG_FILE_LOCKING */
1990 
1991 /* fs/open.c */
1992 
1993 extern int do_truncate(struct dentry *, loff_t start, unsigned int time_attrs,
1994 		       struct file *filp);
1995 extern int do_fallocate(struct file *file, int mode, loff_t offset,
1996 			loff_t len);
1997 extern long do_sys_open(int dfd, const char __user *filename, int flags,
1998 			int mode);
1999 extern struct file *filp_open(const char *, int, int);
2000 extern struct file *file_open_root(struct dentry *, struct vfsmount *,
2001 				   const char *, int);
2002 extern struct file * dentry_open(struct dentry *, struct vfsmount *, int,
2003 				 const struct cred *);
2004 extern int filp_close(struct file *, fl_owner_t id);
2005 extern char * getname(const char __user *);
2006 
2007 /* fs/ioctl.c */
2008 
2009 extern int ioctl_preallocate(struct file *filp, void __user *argp);
2010 
2011 /* fs/dcache.c */
2012 extern void __init vfs_caches_init_early(void);
2013 extern void __init vfs_caches_init(unsigned long);
2014 
2015 extern struct kmem_cache *names_cachep;
2016 
2017 #define __getname_gfp(gfp)	kmem_cache_alloc(names_cachep, (gfp))
2018 #define __getname()		__getname_gfp(GFP_KERNEL)
2019 #define __putname(name)		kmem_cache_free(names_cachep, (void *)(name))
2020 #ifndef CONFIG_AUDITSYSCALL
2021 #define putname(name)   __putname(name)
2022 #else
2023 extern void putname(const char *name);
2024 #endif
2025 
2026 #ifdef CONFIG_BLOCK
2027 extern int register_blkdev(unsigned int, const char *);
2028 extern void unregister_blkdev(unsigned int, const char *);
2029 extern struct block_device *bdget(dev_t);
2030 extern struct block_device *bdgrab(struct block_device *bdev);
2031 extern void bd_set_size(struct block_device *, loff_t size);
2032 extern void bd_forget(struct inode *inode);
2033 extern void bdput(struct block_device *);
2034 extern void invalidate_bdev(struct block_device *);
2035 extern int sync_blockdev(struct block_device *bdev);
2036 extern struct super_block *freeze_bdev(struct block_device *);
2037 extern void emergency_thaw_all(void);
2038 extern int thaw_bdev(struct block_device *bdev, struct super_block *sb);
2039 extern int fsync_bdev(struct block_device *);
2040 #else
bd_forget(struct inode * inode)2041 static inline void bd_forget(struct inode *inode) {}
sync_blockdev(struct block_device * bdev)2042 static inline int sync_blockdev(struct block_device *bdev) { return 0; }
invalidate_bdev(struct block_device * bdev)2043 static inline void invalidate_bdev(struct block_device *bdev) {}
2044 
freeze_bdev(struct block_device * sb)2045 static inline struct super_block *freeze_bdev(struct block_device *sb)
2046 {
2047 	return NULL;
2048 }
2049 
thaw_bdev(struct block_device * bdev,struct super_block * sb)2050 static inline int thaw_bdev(struct block_device *bdev, struct super_block *sb)
2051 {
2052 	return 0;
2053 }
2054 #endif
2055 extern int sync_filesystem(struct super_block *);
2056 extern const struct file_operations def_blk_fops;
2057 extern const struct file_operations def_chr_fops;
2058 extern const struct file_operations bad_sock_fops;
2059 extern const struct file_operations def_fifo_fops;
2060 #ifdef CONFIG_BLOCK
2061 extern int ioctl_by_bdev(struct block_device *, unsigned, unsigned long);
2062 extern int blkdev_ioctl(struct block_device *, fmode_t, unsigned, unsigned long);
2063 extern long compat_blkdev_ioctl(struct file *, unsigned, unsigned long);
2064 extern int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder);
2065 extern struct block_device *blkdev_get_by_path(const char *path, fmode_t mode,
2066 					       void *holder);
2067 extern struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode,
2068 					      void *holder);
2069 extern int blkdev_put(struct block_device *bdev, fmode_t mode);
2070 #ifdef CONFIG_SYSFS
2071 extern int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk);
2072 extern void bd_unlink_disk_holder(struct block_device *bdev,
2073 				  struct gendisk *disk);
2074 #else
bd_link_disk_holder(struct block_device * bdev,struct gendisk * disk)2075 static inline int bd_link_disk_holder(struct block_device *bdev,
2076 				      struct gendisk *disk)
2077 {
2078 	return 0;
2079 }
bd_unlink_disk_holder(struct block_device * bdev,struct gendisk * disk)2080 static inline void bd_unlink_disk_holder(struct block_device *bdev,
2081 					 struct gendisk *disk)
2082 {
2083 }
2084 #endif
2085 #endif
2086 
2087 /* fs/char_dev.c */
2088 #define CHRDEV_MAJOR_HASH_SIZE	255
2089 extern int alloc_chrdev_region(dev_t *, unsigned, unsigned, const char *);
2090 extern int register_chrdev_region(dev_t, unsigned, const char *);
2091 extern int __register_chrdev(unsigned int major, unsigned int baseminor,
2092 			     unsigned int count, const char *name,
2093 			     const struct file_operations *fops);
2094 extern void __unregister_chrdev(unsigned int major, unsigned int baseminor,
2095 				unsigned int count, const char *name);
2096 extern void unregister_chrdev_region(dev_t, unsigned);
2097 extern void chrdev_show(struct seq_file *,off_t);
2098 
register_chrdev(unsigned int major,const char * name,const struct file_operations * fops)2099 static inline int register_chrdev(unsigned int major, const char *name,
2100 				  const struct file_operations *fops)
2101 {
2102 	return __register_chrdev(major, 0, 256, name, fops);
2103 }
2104 
unregister_chrdev(unsigned int major,const char * name)2105 static inline void unregister_chrdev(unsigned int major, const char *name)
2106 {
2107 	__unregister_chrdev(major, 0, 256, name);
2108 }
2109 
2110 /* fs/block_dev.c */
2111 #define BDEVNAME_SIZE	32	/* Largest string for a blockdev identifier */
2112 #define BDEVT_SIZE	10	/* Largest string for MAJ:MIN for blkdev */
2113 
2114 #ifdef CONFIG_BLOCK
2115 #define BLKDEV_MAJOR_HASH_SIZE	255
2116 extern const char *__bdevname(dev_t, char *buffer);
2117 extern const char *bdevname(struct block_device *bdev, char *buffer);
2118 extern struct block_device *lookup_bdev(const char *);
2119 extern void blkdev_show(struct seq_file *,off_t);
2120 
2121 #else
2122 #define BLKDEV_MAJOR_HASH_SIZE	0
2123 #endif
2124 
2125 extern void init_special_inode(struct inode *, umode_t, dev_t);
2126 
2127 /* Invalid inode operations -- fs/bad_inode.c */
2128 extern void make_bad_inode(struct inode *);
2129 extern int is_bad_inode(struct inode *);
2130 
2131 extern const struct file_operations read_pipefifo_fops;
2132 extern const struct file_operations write_pipefifo_fops;
2133 extern const struct file_operations rdwr_pipefifo_fops;
2134 
2135 extern int fs_may_remount_ro(struct super_block *);
2136 
2137 #ifdef CONFIG_BLOCK
2138 /*
2139  * return READ, READA, or WRITE
2140  */
2141 #define bio_rw(bio)		((bio)->bi_rw & (RW_MASK | RWA_MASK))
2142 
2143 /*
2144  * return data direction, READ or WRITE
2145  */
2146 #define bio_data_dir(bio)	((bio)->bi_rw & 1)
2147 
2148 extern void check_disk_size_change(struct gendisk *disk,
2149 				   struct block_device *bdev);
2150 extern int revalidate_disk(struct gendisk *);
2151 extern int check_disk_change(struct block_device *);
2152 extern int __invalidate_device(struct block_device *, bool);
2153 extern int invalidate_partition(struct gendisk *, int);
2154 #endif
2155 unsigned long invalidate_mapping_pages(struct address_space *mapping,
2156 					pgoff_t start, pgoff_t end);
2157 
invalidate_remote_inode(struct inode * inode)2158 static inline void invalidate_remote_inode(struct inode *inode)
2159 {
2160 	if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2161 	    S_ISLNK(inode->i_mode))
2162 		invalidate_mapping_pages(inode->i_mapping, 0, -1);
2163 }
2164 extern int invalidate_inode_pages2(struct address_space *mapping);
2165 extern int invalidate_inode_pages2_range(struct address_space *mapping,
2166 					 pgoff_t start, pgoff_t end);
2167 extern int write_inode_now(struct inode *, int);
2168 extern int filemap_fdatawrite(struct address_space *);
2169 extern int filemap_flush(struct address_space *);
2170 extern int filemap_fdatawait(struct address_space *);
2171 extern int filemap_fdatawait_range(struct address_space *, loff_t lstart,
2172 				   loff_t lend);
2173 extern int filemap_write_and_wait(struct address_space *mapping);
2174 extern int filemap_write_and_wait_range(struct address_space *mapping,
2175 				        loff_t lstart, loff_t lend);
2176 extern int __filemap_fdatawrite_range(struct address_space *mapping,
2177 				loff_t start, loff_t end, int sync_mode);
2178 extern int filemap_fdatawrite_range(struct address_space *mapping,
2179 				loff_t start, loff_t end);
2180 
2181 extern int vfs_fsync_range(struct file *file, loff_t start, loff_t end,
2182 			   int datasync);
2183 extern int vfs_fsync(struct file *file, int datasync);
2184 extern int generic_write_sync(struct file *file, loff_t pos, loff_t count);
2185 extern void sync_supers(void);
2186 extern void emergency_sync(void);
2187 extern void emergency_remount(void);
2188 #ifdef CONFIG_BLOCK
2189 extern sector_t bmap(struct inode *, sector_t);
2190 #endif
2191 extern int notify_change(struct dentry *, struct iattr *);
2192 extern int inode_permission(struct inode *, int);
2193 extern int generic_permission(struct inode *, int, unsigned int,
2194 		int (*check_acl)(struct inode *, int, unsigned int));
2195 
execute_ok(struct inode * inode)2196 static inline bool execute_ok(struct inode *inode)
2197 {
2198 	return (inode->i_mode & S_IXUGO) || S_ISDIR(inode->i_mode);
2199 }
2200 
2201 extern int get_write_access(struct inode *);
2202 extern int deny_write_access(struct file *);
put_write_access(struct inode * inode)2203 static inline void put_write_access(struct inode * inode)
2204 {
2205 	atomic_dec(&inode->i_writecount);
2206 }
allow_write_access(struct file * file)2207 static inline void allow_write_access(struct file *file)
2208 {
2209 	if (file)
2210 		atomic_inc(&file->f_path.dentry->d_inode->i_writecount);
2211 }
2212 #ifdef CONFIG_IMA
i_readcount_dec(struct inode * inode)2213 static inline void i_readcount_dec(struct inode *inode)
2214 {
2215 	BUG_ON(!atomic_read(&inode->i_readcount));
2216 	atomic_dec(&inode->i_readcount);
2217 }
i_readcount_inc(struct inode * inode)2218 static inline void i_readcount_inc(struct inode *inode)
2219 {
2220 	atomic_inc(&inode->i_readcount);
2221 }
2222 #else
i_readcount_dec(struct inode * inode)2223 static inline void i_readcount_dec(struct inode *inode)
2224 {
2225 	return;
2226 }
i_readcount_inc(struct inode * inode)2227 static inline void i_readcount_inc(struct inode *inode)
2228 {
2229 	return;
2230 }
2231 #endif
2232 extern int do_pipe_flags(int *, int);
2233 extern struct file *create_read_pipe(struct file *f, int flags);
2234 extern struct file *create_write_pipe(int flags);
2235 extern void free_write_pipe(struct file *);
2236 
2237 extern int kernel_read(struct file *, loff_t, char *, unsigned long);
2238 extern struct file * open_exec(const char *);
2239 
2240 /* fs/dcache.c -- generic fs support functions */
2241 extern int is_subdir(struct dentry *, struct dentry *);
2242 extern int path_is_under(struct path *, struct path *);
2243 extern ino_t find_inode_number(struct dentry *, struct qstr *);
2244 
2245 #include <linux/err.h>
2246 
2247 /* needed for stackable file system support */
2248 extern loff_t default_llseek(struct file *file, loff_t offset, int origin);
2249 
2250 extern loff_t vfs_llseek(struct file *file, loff_t offset, int origin);
2251 
2252 extern int inode_init_always(struct super_block *, struct inode *);
2253 extern void inode_init_once(struct inode *);
2254 extern void address_space_init_once(struct address_space *mapping);
2255 extern void ihold(struct inode * inode);
2256 extern void iput(struct inode *);
2257 extern struct inode * igrab(struct inode *);
2258 extern ino_t iunique(struct super_block *, ino_t);
2259 extern int inode_needs_sync(struct inode *inode);
2260 extern int generic_delete_inode(struct inode *inode);
2261 extern int generic_drop_inode(struct inode *inode);
2262 
2263 extern struct inode *ilookup5_nowait(struct super_block *sb,
2264 		unsigned long hashval, int (*test)(struct inode *, void *),
2265 		void *data);
2266 extern struct inode *ilookup5(struct super_block *sb, unsigned long hashval,
2267 		int (*test)(struct inode *, void *), void *data);
2268 extern struct inode *ilookup(struct super_block *sb, unsigned long ino);
2269 
2270 extern struct inode * iget5_locked(struct super_block *, unsigned long, int (*test)(struct inode *, void *), int (*set)(struct inode *, void *), void *);
2271 extern struct inode * iget_locked(struct super_block *, unsigned long);
2272 extern int insert_inode_locked4(struct inode *, unsigned long, int (*test)(struct inode *, void *), void *);
2273 extern int insert_inode_locked(struct inode *);
2274 extern void unlock_new_inode(struct inode *);
2275 extern unsigned int get_next_ino(void);
2276 
2277 extern void __iget(struct inode * inode);
2278 extern void iget_failed(struct inode *);
2279 extern void end_writeback(struct inode *);
2280 extern void __destroy_inode(struct inode *);
2281 extern struct inode *new_inode(struct super_block *);
2282 extern void free_inode_nonrcu(struct inode *inode);
2283 extern int should_remove_suid(struct dentry *);
2284 extern int file_remove_suid(struct file *);
2285 
2286 extern void __insert_inode_hash(struct inode *, unsigned long hashval);
2287 extern void remove_inode_hash(struct inode *);
insert_inode_hash(struct inode * inode)2288 static inline void insert_inode_hash(struct inode *inode)
2289 {
2290 	__insert_inode_hash(inode, inode->i_ino);
2291 }
2292 extern void inode_sb_list_add(struct inode *inode);
2293 
2294 #ifdef CONFIG_BLOCK
2295 extern void submit_bio(int, struct bio *);
2296 extern int bdev_read_only(struct block_device *);
2297 #endif
2298 extern int set_blocksize(struct block_device *, int);
2299 extern int sb_set_blocksize(struct super_block *, int);
2300 extern int sb_min_blocksize(struct super_block *, int);
2301 
2302 extern int generic_file_mmap(struct file *, struct vm_area_struct *);
2303 extern int generic_file_readonly_mmap(struct file *, struct vm_area_struct *);
2304 extern int file_read_actor(read_descriptor_t * desc, struct page *page, unsigned long offset, unsigned long size);
2305 int generic_write_checks(struct file *file, loff_t *pos, size_t *count, int isblk);
2306 extern ssize_t generic_file_aio_read(struct kiocb *, const struct iovec *, unsigned long, loff_t);
2307 extern ssize_t __generic_file_aio_write(struct kiocb *, const struct iovec *, unsigned long,
2308 		loff_t *);
2309 extern ssize_t generic_file_aio_write(struct kiocb *, const struct iovec *, unsigned long, loff_t);
2310 extern ssize_t generic_file_direct_write(struct kiocb *, const struct iovec *,
2311 		unsigned long *, loff_t, loff_t *, size_t, size_t);
2312 extern ssize_t generic_file_buffered_write(struct kiocb *, const struct iovec *,
2313 		unsigned long, loff_t, loff_t *, size_t, ssize_t);
2314 extern ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos);
2315 extern ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos);
2316 extern int generic_segment_checks(const struct iovec *iov,
2317 		unsigned long *nr_segs, size_t *count, int access_flags);
2318 
2319 /* fs/block_dev.c */
2320 extern ssize_t blkdev_aio_write(struct kiocb *iocb, const struct iovec *iov,
2321 				unsigned long nr_segs, loff_t pos);
2322 extern int blkdev_fsync(struct file *filp, int datasync);
2323 
2324 /* fs/splice.c */
2325 extern ssize_t generic_file_splice_read(struct file *, loff_t *,
2326 		struct pipe_inode_info *, size_t, unsigned int);
2327 extern ssize_t default_file_splice_read(struct file *, loff_t *,
2328 		struct pipe_inode_info *, size_t, unsigned int);
2329 extern ssize_t generic_file_splice_write(struct pipe_inode_info *,
2330 		struct file *, loff_t *, size_t, unsigned int);
2331 extern ssize_t generic_splice_sendpage(struct pipe_inode_info *pipe,
2332 		struct file *out, loff_t *, size_t len, unsigned int flags);
2333 extern long do_splice_direct(struct file *in, loff_t *ppos, struct file *out,
2334 		size_t len, unsigned int flags);
2335 
2336 extern void
2337 file_ra_state_init(struct file_ra_state *ra, struct address_space *mapping);
2338 extern loff_t noop_llseek(struct file *file, loff_t offset, int origin);
2339 extern loff_t no_llseek(struct file *file, loff_t offset, int origin);
2340 extern loff_t generic_file_llseek(struct file *file, loff_t offset, int origin);
2341 extern loff_t generic_file_llseek_unlocked(struct file *file, loff_t offset,
2342 			int origin);
2343 extern int generic_file_open(struct inode * inode, struct file * filp);
2344 extern int nonseekable_open(struct inode * inode, struct file * filp);
2345 
2346 #ifdef CONFIG_FS_XIP
2347 extern ssize_t xip_file_read(struct file *filp, char __user *buf, size_t len,
2348 			     loff_t *ppos);
2349 extern int xip_file_mmap(struct file * file, struct vm_area_struct * vma);
2350 extern ssize_t xip_file_write(struct file *filp, const char __user *buf,
2351 			      size_t len, loff_t *ppos);
2352 extern int xip_truncate_page(struct address_space *mapping, loff_t from);
2353 #else
xip_truncate_page(struct address_space * mapping,loff_t from)2354 static inline int xip_truncate_page(struct address_space *mapping, loff_t from)
2355 {
2356 	return 0;
2357 }
2358 #endif
2359 
2360 #ifdef CONFIG_BLOCK
2361 typedef void (dio_submit_t)(int rw, struct bio *bio, struct inode *inode,
2362 			    loff_t file_offset);
2363 
2364 enum {
2365 	/* need locking between buffered and direct access */
2366 	DIO_LOCKING	= 0x01,
2367 
2368 	/* filesystem does not support filling holes */
2369 	DIO_SKIP_HOLES	= 0x02,
2370 };
2371 
2372 void dio_end_io(struct bio *bio, int error);
2373 
2374 ssize_t __blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode,
2375 	struct block_device *bdev, const struct iovec *iov, loff_t offset,
2376 	unsigned long nr_segs, get_block_t get_block, dio_iodone_t end_io,
2377 	dio_submit_t submit_io,	int flags);
2378 
blockdev_direct_IO(int rw,struct kiocb * iocb,struct inode * inode,struct block_device * bdev,const struct iovec * iov,loff_t offset,unsigned long nr_segs,get_block_t get_block,dio_iodone_t end_io)2379 static inline ssize_t blockdev_direct_IO(int rw, struct kiocb *iocb,
2380 	struct inode *inode, struct block_device *bdev, const struct iovec *iov,
2381 	loff_t offset, unsigned long nr_segs, get_block_t get_block,
2382 	dio_iodone_t end_io)
2383 {
2384 	return __blockdev_direct_IO(rw, iocb, inode, bdev, iov, offset,
2385 				    nr_segs, get_block, end_io, NULL,
2386 				    DIO_LOCKING | DIO_SKIP_HOLES);
2387 }
2388 #endif
2389 
2390 extern const struct file_operations generic_ro_fops;
2391 
2392 #define special_file(m) (S_ISCHR(m)||S_ISBLK(m)||S_ISFIFO(m)||S_ISSOCK(m))
2393 
2394 extern int vfs_readlink(struct dentry *, char __user *, int, const char *);
2395 extern int vfs_follow_link(struct nameidata *, const char *);
2396 extern int page_readlink(struct dentry *, char __user *, int);
2397 extern void *page_follow_link_light(struct dentry *, struct nameidata *);
2398 extern void page_put_link(struct dentry *, struct nameidata *, void *);
2399 extern int __page_symlink(struct inode *inode, const char *symname, int len,
2400 		int nofs);
2401 extern int page_symlink(struct inode *inode, const char *symname, int len);
2402 extern const struct inode_operations page_symlink_inode_operations;
2403 extern int generic_readlink(struct dentry *, char __user *, int);
2404 extern void generic_fillattr(struct inode *, struct kstat *);
2405 extern int vfs_getattr(struct vfsmount *, struct dentry *, struct kstat *);
2406 void __inode_add_bytes(struct inode *inode, loff_t bytes);
2407 void inode_add_bytes(struct inode *inode, loff_t bytes);
2408 void inode_sub_bytes(struct inode *inode, loff_t bytes);
2409 loff_t inode_get_bytes(struct inode *inode);
2410 void inode_set_bytes(struct inode *inode, loff_t bytes);
2411 
2412 extern int vfs_readdir(struct file *, filldir_t, void *);
2413 
2414 extern int vfs_stat(const char __user *, struct kstat *);
2415 extern int vfs_lstat(const char __user *, struct kstat *);
2416 extern int vfs_fstat(unsigned int, struct kstat *);
2417 extern int vfs_fstatat(int , const char __user *, struct kstat *, int);
2418 
2419 extern int do_vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd,
2420 		    unsigned long arg);
2421 extern int __generic_block_fiemap(struct inode *inode,
2422 				  struct fiemap_extent_info *fieinfo,
2423 				  loff_t start, loff_t len,
2424 				  get_block_t *get_block);
2425 extern int generic_block_fiemap(struct inode *inode,
2426 				struct fiemap_extent_info *fieinfo, u64 start,
2427 				u64 len, get_block_t *get_block);
2428 
2429 extern void get_filesystem(struct file_system_type *fs);
2430 extern void put_filesystem(struct file_system_type *fs);
2431 extern struct file_system_type *get_fs_type(const char *name);
2432 extern struct super_block *get_super(struct block_device *);
2433 extern struct super_block *get_active_super(struct block_device *bdev);
2434 extern struct super_block *user_get_super(dev_t);
2435 extern void drop_super(struct super_block *sb);
2436 extern void iterate_supers(void (*)(struct super_block *, void *), void *);
2437 
2438 extern int dcache_dir_open(struct inode *, struct file *);
2439 extern int dcache_dir_close(struct inode *, struct file *);
2440 extern loff_t dcache_dir_lseek(struct file *, loff_t, int);
2441 extern int dcache_readdir(struct file *, void *, filldir_t);
2442 extern int simple_setattr(struct dentry *, struct iattr *);
2443 extern int simple_getattr(struct vfsmount *, struct dentry *, struct kstat *);
2444 extern int simple_statfs(struct dentry *, struct kstatfs *);
2445 extern int simple_link(struct dentry *, struct inode *, struct dentry *);
2446 extern int simple_unlink(struct inode *, struct dentry *);
2447 extern int simple_rmdir(struct inode *, struct dentry *);
2448 extern int simple_rename(struct inode *, struct dentry *, struct inode *, struct dentry *);
2449 extern int noop_fsync(struct file *, int);
2450 extern int simple_empty(struct dentry *);
2451 extern int simple_readpage(struct file *file, struct page *page);
2452 extern int simple_write_begin(struct file *file, struct address_space *mapping,
2453 			loff_t pos, unsigned len, unsigned flags,
2454 			struct page **pagep, void **fsdata);
2455 extern int simple_write_end(struct file *file, struct address_space *mapping,
2456 			loff_t pos, unsigned len, unsigned copied,
2457 			struct page *page, void *fsdata);
2458 
2459 extern struct dentry *simple_lookup(struct inode *, struct dentry *, struct nameidata *);
2460 extern ssize_t generic_read_dir(struct file *, char __user *, size_t, loff_t *);
2461 extern const struct file_operations simple_dir_operations;
2462 extern const struct inode_operations simple_dir_inode_operations;
2463 struct tree_descr { char *name; const struct file_operations *ops; int mode; };
2464 struct dentry *d_alloc_name(struct dentry *, const char *);
2465 extern int simple_fill_super(struct super_block *, unsigned long, struct tree_descr *);
2466 extern int simple_pin_fs(struct file_system_type *, struct vfsmount **mount, int *count);
2467 extern void simple_release_fs(struct vfsmount **mount, int *count);
2468 
2469 extern ssize_t simple_read_from_buffer(void __user *to, size_t count,
2470 			loff_t *ppos, const void *from, size_t available);
2471 extern ssize_t simple_write_to_buffer(void *to, size_t available, loff_t *ppos,
2472 		const void __user *from, size_t count);
2473 
2474 extern int generic_file_fsync(struct file *, int);
2475 
2476 extern int generic_check_addressable(unsigned, u64);
2477 
2478 #ifdef CONFIG_MIGRATION
2479 extern int buffer_migrate_page(struct address_space *,
2480 				struct page *, struct page *);
2481 #else
2482 #define buffer_migrate_page NULL
2483 #endif
2484 
2485 extern int inode_change_ok(const struct inode *, struct iattr *);
2486 extern int inode_newsize_ok(const struct inode *, loff_t offset);
2487 extern void setattr_copy(struct inode *inode, const struct iattr *attr);
2488 
2489 extern void file_update_time(struct file *file);
2490 
2491 extern int generic_show_options(struct seq_file *m, struct vfsmount *mnt);
2492 extern void save_mount_options(struct super_block *sb, char *options);
2493 extern void replace_mount_options(struct super_block *sb, char *options);
2494 
parent_ino(struct dentry * dentry)2495 static inline ino_t parent_ino(struct dentry *dentry)
2496 {
2497 	ino_t res;
2498 
2499 	/*
2500 	 * Don't strictly need d_lock here? If the parent ino could change
2501 	 * then surely we'd have a deeper race in the caller?
2502 	 */
2503 	spin_lock(&dentry->d_lock);
2504 	res = dentry->d_parent->d_inode->i_ino;
2505 	spin_unlock(&dentry->d_lock);
2506 	return res;
2507 }
2508 
2509 /* Transaction based IO helpers */
2510 
2511 /*
2512  * An argresp is stored in an allocated page and holds the
2513  * size of the argument or response, along with its content
2514  */
2515 struct simple_transaction_argresp {
2516 	ssize_t size;
2517 	char data[0];
2518 };
2519 
2520 #define SIMPLE_TRANSACTION_LIMIT (PAGE_SIZE - sizeof(struct simple_transaction_argresp))
2521 
2522 char *simple_transaction_get(struct file *file, const char __user *buf,
2523 				size_t size);
2524 ssize_t simple_transaction_read(struct file *file, char __user *buf,
2525 				size_t size, loff_t *pos);
2526 int simple_transaction_release(struct inode *inode, struct file *file);
2527 
2528 void simple_transaction_set(struct file *file, size_t n);
2529 
2530 /*
2531  * simple attribute files
2532  *
2533  * These attributes behave similar to those in sysfs:
2534  *
2535  * Writing to an attribute immediately sets a value, an open file can be
2536  * written to multiple times.
2537  *
2538  * Reading from an attribute creates a buffer from the value that might get
2539  * read with multiple read calls. When the attribute has been read
2540  * completely, no further read calls are possible until the file is opened
2541  * again.
2542  *
2543  * All attributes contain a text representation of a numeric value
2544  * that are accessed with the get() and set() functions.
2545  */
2546 #define DEFINE_SIMPLE_ATTRIBUTE(__fops, __get, __set, __fmt)		\
2547 static int __fops ## _open(struct inode *inode, struct file *file)	\
2548 {									\
2549 	__simple_attr_check_format(__fmt, 0ull);			\
2550 	return simple_attr_open(inode, file, __get, __set, __fmt);	\
2551 }									\
2552 static const struct file_operations __fops = {				\
2553 	.owner	 = THIS_MODULE,						\
2554 	.open	 = __fops ## _open,					\
2555 	.release = simple_attr_release,					\
2556 	.read	 = simple_attr_read,					\
2557 	.write	 = simple_attr_write,					\
2558 	.llseek	 = generic_file_llseek,					\
2559 };
2560 
2561 static inline void __attribute__((format(printf, 1, 2)))
__simple_attr_check_format(const char * fmt,...)2562 __simple_attr_check_format(const char *fmt, ...)
2563 {
2564 	/* don't do anything, just let the compiler check the arguments; */
2565 }
2566 
2567 int simple_attr_open(struct inode *inode, struct file *file,
2568 		     int (*get)(void *, u64 *), int (*set)(void *, u64),
2569 		     const char *fmt);
2570 int simple_attr_release(struct inode *inode, struct file *file);
2571 ssize_t simple_attr_read(struct file *file, char __user *buf,
2572 			 size_t len, loff_t *ppos);
2573 ssize_t simple_attr_write(struct file *file, const char __user *buf,
2574 			  size_t len, loff_t *ppos);
2575 
2576 struct ctl_table;
2577 int proc_nr_files(struct ctl_table *table, int write,
2578 		  void __user *buffer, size_t *lenp, loff_t *ppos);
2579 int proc_nr_dentry(struct ctl_table *table, int write,
2580 		  void __user *buffer, size_t *lenp, loff_t *ppos);
2581 int proc_nr_inodes(struct ctl_table *table, int write,
2582 		   void __user *buffer, size_t *lenp, loff_t *ppos);
2583 int __init get_filesystem_list(char *buf);
2584 
2585 #define __FMODE_EXEC		((__force int) FMODE_EXEC)
2586 #define __FMODE_NONOTIFY	((__force int) FMODE_NONOTIFY)
2587 
2588 #define ACC_MODE(x) ("\004\002\006\006"[(x)&O_ACCMODE])
2589 #define OPEN_FMODE(flag) ((__force fmode_t)(((flag + 1) & O_ACCMODE) | \
2590 					    (flag & __FMODE_NONOTIFY)))
2591 
is_sxid(mode_t mode)2592 static inline int is_sxid(mode_t mode)
2593 {
2594 	return (mode & S_ISUID) || ((mode & S_ISGID) && (mode & S_IXGRP));
2595 }
2596 
inode_has_no_xattr(struct inode * inode)2597 static inline void inode_has_no_xattr(struct inode *inode)
2598 {
2599 	if (!is_sxid(inode->i_mode) && (inode->i_sb->s_flags & MS_NOSEC))
2600 		inode->i_flags |= S_NOSEC;
2601 }
2602 
2603 #endif /* __KERNEL__ */
2604 #endif /* _LINUX_FS_H */
2605