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1da177e4
LT
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/config.h>
10#include <linux/limits.h>
11#include <linux/ioctl.h>
12
13/*
14 * It's silly to have NR_OPEN bigger than NR_FILE, but you can change
15 * the file limit at runtime and only root can increase the per-process
16 * nr_file rlimit, so it's safe to set up a ridiculously high absolute
17 * upper limit on files-per-process.
18 *
19 * Some programs (notably those using select()) may have to be
20 * recompiled to take full advantage of the new limits..
21 */
22
23/* Fixed constants first: */
24#undef NR_OPEN
25#define NR_OPEN (1024*1024) /* Absolute upper limit on fd num */
26#define INR_OPEN 1024 /* Initial setting for nfile rlimits */
27
28#define BLOCK_SIZE_BITS 10
29#define BLOCK_SIZE (1<<BLOCK_SIZE_BITS)
30
31/* And dynamically-tunable limits and defaults: */
32struct files_stat_struct {
33 int nr_files; /* read only */
34 int nr_free_files; /* read only */
35 int max_files; /* tunable */
36};
37extern struct files_stat_struct files_stat;
38
39struct inodes_stat_t {
40 int nr_inodes;
41 int nr_unused;
42 int dummy[5];
43};
44extern struct inodes_stat_t inodes_stat;
45
46extern int leases_enable, lease_break_time;
47
48#ifdef CONFIG_DNOTIFY
49extern int dir_notify_enable;
50#endif
51
52#define NR_FILE 8192 /* this can well be larger on a larger system */
53
54#define MAY_EXEC 1
55#define MAY_WRITE 2
56#define MAY_READ 4
57#define MAY_APPEND 8
58
59#define FMODE_READ 1
60#define FMODE_WRITE 2
61
62/* Internal kernel extensions */
63#define FMODE_LSEEK 4
64#define FMODE_PREAD 8
65#define FMODE_PWRITE FMODE_PREAD /* These go hand in hand */
66
67#define RW_MASK 1
68#define RWA_MASK 2
69#define READ 0
70#define WRITE 1
71#define READA 2 /* read-ahead - don't block if no resources */
72#define SPECIAL 4 /* For non-blockdevice requests in request queue */
73#define READ_SYNC (READ | (1 << BIO_RW_SYNC))
74#define WRITE_SYNC (WRITE | (1 << BIO_RW_SYNC))
75#define WRITE_BARRIER ((1 << BIO_RW) | (1 << BIO_RW_BARRIER))
76
77#define SEL_IN 1
78#define SEL_OUT 2
79#define SEL_EX 4
80
81/* public flags for file_system_type */
82#define FS_REQUIRES_DEV 1
83#define FS_BINARY_MOUNTDATA 2
84#define FS_REVAL_DOT 16384 /* Check the paths ".", ".." for staleness */
85#define FS_ODD_RENAME 32768 /* Temporary stuff; will go away as soon
86 * as nfs_rename() will be cleaned up
87 */
88/*
89 * These are the fs-independent mount-flags: up to 32 flags are supported
90 */
91#define MS_RDONLY 1 /* Mount read-only */
92#define MS_NOSUID 2 /* Ignore suid and sgid bits */
93#define MS_NODEV 4 /* Disallow access to device special files */
94#define MS_NOEXEC 8 /* Disallow program execution */
95#define MS_SYNCHRONOUS 16 /* Writes are synced at once */
96#define MS_REMOUNT 32 /* Alter flags of a mounted FS */
97#define MS_MANDLOCK 64 /* Allow mandatory locks on an FS */
98#define MS_DIRSYNC 128 /* Directory modifications are synchronous */
99#define MS_NOATIME 1024 /* Do not update access times. */
100#define MS_NODIRATIME 2048 /* Do not update directory access times */
101#define MS_BIND 4096
102#define MS_MOVE 8192
103#define MS_REC 16384
104#define MS_VERBOSE 32768
105#define MS_POSIXACL (1<<16) /* VFS does not apply the umask */
106#define MS_ACTIVE (1<<30)
107#define MS_NOUSER (1<<31)
108
109/*
110 * Superblock flags that can be altered by MS_REMOUNT
111 */
112#define MS_RMT_MASK (MS_RDONLY|MS_SYNCHRONOUS|MS_MANDLOCK|MS_NOATIME|\
113 MS_NODIRATIME)
114
115/*
116 * Old magic mount flag and mask
117 */
118#define MS_MGC_VAL 0xC0ED0000
119#define MS_MGC_MSK 0xffff0000
120
121/* Inode flags - they have nothing to superblock flags now */
122
123#define S_SYNC 1 /* Writes are synced at once */
124#define S_NOATIME 2 /* Do not update access times */
125#define S_APPEND 4 /* Append-only file */
126#define S_IMMUTABLE 8 /* Immutable file */
127#define S_DEAD 16 /* removed, but still open directory */
128#define S_NOQUOTA 32 /* Inode is not counted to quota */
129#define S_DIRSYNC 64 /* Directory modifications are synchronous */
130#define S_NOCMTIME 128 /* Do not update file c/mtime */
131#define S_SWAPFILE 256 /* Do not truncate: swapon got its bmaps */
132#define S_PRIVATE 512 /* Inode is fs-internal */
133
134/*
135 * Note that nosuid etc flags are inode-specific: setting some file-system
136 * flags just means all the inodes inherit those flags by default. It might be
137 * possible to override it selectively if you really wanted to with some
138 * ioctl() that is not currently implemented.
139 *
140 * Exception: MS_RDONLY is always applied to the entire file system.
141 *
142 * Unfortunately, it is possible to change a filesystems flags with it mounted
143 * with files in use. This means that all of the inodes will not have their
144 * i_flags updated. Hence, i_flags no longer inherit the superblock mount
145 * flags, so these have to be checked separately. -- rmk@arm.uk.linux.org
146 */
147#define __IS_FLG(inode,flg) ((inode)->i_sb->s_flags & (flg))
148
149#define IS_RDONLY(inode) ((inode)->i_sb->s_flags & MS_RDONLY)
150#define IS_SYNC(inode) (__IS_FLG(inode, MS_SYNCHRONOUS) || \
151 ((inode)->i_flags & S_SYNC))
152#define IS_DIRSYNC(inode) (__IS_FLG(inode, MS_SYNCHRONOUS|MS_DIRSYNC) || \
153 ((inode)->i_flags & (S_SYNC|S_DIRSYNC)))
154#define IS_MANDLOCK(inode) __IS_FLG(inode, MS_MANDLOCK)
155
156#define IS_NOQUOTA(inode) ((inode)->i_flags & S_NOQUOTA)
157#define IS_APPEND(inode) ((inode)->i_flags & S_APPEND)
158#define IS_IMMUTABLE(inode) ((inode)->i_flags & S_IMMUTABLE)
159#define IS_NOATIME(inode) (__IS_FLG(inode, MS_NOATIME) || ((inode)->i_flags & S_NOATIME))
160#define IS_NODIRATIME(inode) __IS_FLG(inode, MS_NODIRATIME)
161#define IS_POSIXACL(inode) __IS_FLG(inode, MS_POSIXACL)
162
163#define IS_DEADDIR(inode) ((inode)->i_flags & S_DEAD)
164#define IS_NOCMTIME(inode) ((inode)->i_flags & S_NOCMTIME)
165#define IS_SWAPFILE(inode) ((inode)->i_flags & S_SWAPFILE)
166#define IS_PRIVATE(inode) ((inode)->i_flags & S_PRIVATE)
167
168/* the read-only stuff doesn't really belong here, but any other place is
169 probably as bad and I don't want to create yet another include file. */
170
171#define BLKROSET _IO(0x12,93) /* set device read-only (0 = read-write) */
172#define BLKROGET _IO(0x12,94) /* get read-only status (0 = read_write) */
173#define BLKRRPART _IO(0x12,95) /* re-read partition table */
174#define BLKGETSIZE _IO(0x12,96) /* return device size /512 (long *arg) */
175#define BLKFLSBUF _IO(0x12,97) /* flush buffer cache */
176#define BLKRASET _IO(0x12,98) /* set read ahead for block device */
177#define BLKRAGET _IO(0x12,99) /* get current read ahead setting */
178#define BLKFRASET _IO(0x12,100)/* set filesystem (mm/filemap.c) read-ahead */
179#define BLKFRAGET _IO(0x12,101)/* get filesystem (mm/filemap.c) read-ahead */
180#define BLKSECTSET _IO(0x12,102)/* set max sectors per request (ll_rw_blk.c) */
181#define BLKSECTGET _IO(0x12,103)/* get max sectors per request (ll_rw_blk.c) */
182#define BLKSSZGET _IO(0x12,104)/* get block device sector size */
183#if 0
184#define BLKPG _IO(0x12,105)/* See blkpg.h */
185
186/* Some people are morons. Do not use sizeof! */
187
188#define BLKELVGET _IOR(0x12,106,size_t)/* elevator get */
189#define BLKELVSET _IOW(0x12,107,size_t)/* elevator set */
190/* This was here just to show that the number is taken -
191 probably all these _IO(0x12,*) ioctls should be moved to blkpg.h. */
192#endif
193/* A jump here: 108-111 have been used for various private purposes. */
194#define BLKBSZGET _IOR(0x12,112,size_t)
195#define BLKBSZSET _IOW(0x12,113,size_t)
196#define BLKGETSIZE64 _IOR(0x12,114,size_t) /* return device size in bytes (u64 *arg) */
197
198#define BMAP_IOCTL 1 /* obsolete - kept for compatibility */
199#define FIBMAP _IO(0x00,1) /* bmap access */
200#define FIGETBSZ _IO(0x00,2) /* get the block size used for bmap */
201
202#ifdef __KERNEL__
203
204#include <linux/linkage.h>
205#include <linux/wait.h>
206#include <linux/types.h>
207#include <linux/kdev_t.h>
208#include <linux/dcache.h>
209#include <linux/stat.h>
210#include <linux/cache.h>
211#include <linux/kobject.h>
212#include <linux/list.h>
213#include <linux/radix-tree.h>
214#include <linux/prio_tree.h>
215#include <linux/init.h>
22e2c507 216#include <linux/sched.h>
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217
218#include <asm/atomic.h>
219#include <asm/semaphore.h>
220#include <asm/byteorder.h>
221
222struct iovec;
223struct nameidata;
92198f7e 224struct kiocb;
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225struct pipe_inode_info;
226struct poll_table_struct;
227struct kstatfs;
228struct vm_area_struct;
229struct vfsmount;
230
231/* Used to be a macro which just called the function, now just a function */
232extern void update_atime (struct inode *);
233
234extern void __init inode_init(unsigned long);
235extern void __init inode_init_early(void);
236extern void __init mnt_init(unsigned long);
237extern void __init files_init(unsigned long);
238
239struct buffer_head;
240typedef int (get_block_t)(struct inode *inode, sector_t iblock,
241 struct buffer_head *bh_result, int create);
242typedef int (get_blocks_t)(struct inode *inode, sector_t iblock,
243 unsigned long max_blocks,
244 struct buffer_head *bh_result, int create);
92198f7e 245typedef void (dio_iodone_t)(struct kiocb *iocb, loff_t offset,
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246 ssize_t bytes, void *private);
247
248/*
249 * Attribute flags. These should be or-ed together to figure out what
250 * has been changed!
251 */
252#define ATTR_MODE 1
253#define ATTR_UID 2
254#define ATTR_GID 4
255#define ATTR_SIZE 8
256#define ATTR_ATIME 16
257#define ATTR_MTIME 32
258#define ATTR_CTIME 64
259#define ATTR_ATIME_SET 128
260#define ATTR_MTIME_SET 256
261#define ATTR_FORCE 512 /* Not a change, but a change it */
262#define ATTR_ATTR_FLAG 1024
263#define ATTR_KILL_SUID 2048
264#define ATTR_KILL_SGID 4096
265
266/*
267 * This is the Inode Attributes structure, used for notify_change(). It
268 * uses the above definitions as flags, to know which values have changed.
269 * Also, in this manner, a Filesystem can look at only the values it cares
270 * about. Basically, these are the attributes that the VFS layer can
271 * request to change from the FS layer.
272 *
273 * Derek Atkins <warlord@MIT.EDU> 94-10-20
274 */
275struct iattr {
276 unsigned int ia_valid;
277 umode_t ia_mode;
278 uid_t ia_uid;
279 gid_t ia_gid;
280 loff_t ia_size;
281 struct timespec ia_atime;
282 struct timespec ia_mtime;
283 struct timespec ia_ctime;
284 unsigned int ia_attr_flags;
285};
286
287/*
288 * This is the inode attributes flag definitions
289 */
290#define ATTR_FLAG_SYNCRONOUS 1 /* Syncronous write */
291#define ATTR_FLAG_NOATIME 2 /* Don't update atime */
292#define ATTR_FLAG_APPEND 4 /* Append-only file */
293#define ATTR_FLAG_IMMUTABLE 8 /* Immutable file */
294#define ATTR_FLAG_NODIRATIME 16 /* Don't update atime for directory */
295
296/*
297 * Includes for diskquotas.
298 */
299#include <linux/quota.h>
300
301/*
302 * oh the beauties of C type declarations.
303 */
304struct page;
305struct address_space;
306struct writeback_control;
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307
308struct address_space_operations {
309 int (*writepage)(struct page *page, struct writeback_control *wbc);
310 int (*readpage)(struct file *, struct page *);
311 int (*sync_page)(struct page *);
312
313 /* Write back some dirty pages from this mapping. */
314 int (*writepages)(struct address_space *, struct writeback_control *);
315
316 /* Set a page dirty */
317 int (*set_page_dirty)(struct page *page);
318
319 int (*readpages)(struct file *filp, struct address_space *mapping,
320 struct list_head *pages, unsigned nr_pages);
321
322 /*
323 * ext3 requires that a successful prepare_write() call be followed
324 * by a commit_write() call - they must be balanced
325 */
326 int (*prepare_write)(struct file *, struct page *, unsigned, unsigned);
327 int (*commit_write)(struct file *, struct page *, unsigned, unsigned);
328 /* Unfortunately this kludge is needed for FIBMAP. Don't use it */
329 sector_t (*bmap)(struct address_space *, sector_t);
330 int (*invalidatepage) (struct page *, unsigned long);
331 int (*releasepage) (struct page *, int);
332 ssize_t (*direct_IO)(int, struct kiocb *, const struct iovec *iov,
333 loff_t offset, unsigned long nr_segs);
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334 struct page* (*get_xip_page)(struct address_space *, sector_t,
335 int);
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336};
337
338struct backing_dev_info;
339struct address_space {
340 struct inode *host; /* owner: inode, block_device */
341 struct radix_tree_root page_tree; /* radix tree of all pages */
342 rwlock_t tree_lock; /* and rwlock protecting it */
343 unsigned int i_mmap_writable;/* count VM_SHARED mappings */
344 struct prio_tree_root i_mmap; /* tree of private and shared mappings */
345 struct list_head i_mmap_nonlinear;/*list VM_NONLINEAR mappings */
346 spinlock_t i_mmap_lock; /* protect tree, count, list */
347 unsigned int truncate_count; /* Cover race condition with truncate */
348 unsigned long nrpages; /* number of total pages */
349 pgoff_t writeback_index;/* writeback starts here */
350 struct address_space_operations *a_ops; /* methods */
351 unsigned long flags; /* error bits/gfp mask */
352 struct backing_dev_info *backing_dev_info; /* device readahead, etc */
353 spinlock_t private_lock; /* for use by the address_space */
354 struct list_head private_list; /* ditto */
355 struct address_space *assoc_mapping; /* ditto */
356} __attribute__((aligned(sizeof(long))));
357 /*
358 * On most architectures that alignment is already the case; but
359 * must be enforced here for CRIS, to let the least signficant bit
360 * of struct page's "mapping" pointer be used for PAGE_MAPPING_ANON.
361 */
362
363struct block_device {
364 dev_t bd_dev; /* not a kdev_t - it's a search key */
365 struct inode * bd_inode; /* will die */
366 int bd_openers;
367 struct semaphore bd_sem; /* open/close mutex */
368 struct semaphore bd_mount_sem; /* mount mutex */
369 struct list_head bd_inodes;
370 void * bd_holder;
371 int bd_holders;
372 struct block_device * bd_contains;
373 unsigned bd_block_size;
374 struct hd_struct * bd_part;
375 /* number of times partitions within this device have been opened. */
376 unsigned bd_part_count;
377 int bd_invalidated;
378 struct gendisk * bd_disk;
379 struct list_head bd_list;
380 struct backing_dev_info *bd_inode_backing_dev_info;
381 /*
382 * Private data. You must have bd_claim'ed the block_device
383 * to use this. NOTE: bd_claim allows an owner to claim
384 * the same device multiple times, the owner must take special
385 * care to not mess up bd_private for that case.
386 */
387 unsigned long bd_private;
388};
389
390/*
391 * Radix-tree tags, for tagging dirty and writeback pages within the pagecache
392 * radix trees
393 */
394#define PAGECACHE_TAG_DIRTY 0
395#define PAGECACHE_TAG_WRITEBACK 1
396
397int mapping_tagged(struct address_space *mapping, int tag);
398
399/*
400 * Might pages of this file be mapped into userspace?
401 */
402static inline int mapping_mapped(struct address_space *mapping)
403{
404 return !prio_tree_empty(&mapping->i_mmap) ||
405 !list_empty(&mapping->i_mmap_nonlinear);
406}
407
408/*
409 * Might pages of this file have been modified in userspace?
410 * Note that i_mmap_writable counts all VM_SHARED vmas: do_mmap_pgoff
411 * marks vma as VM_SHARED if it is shared, and the file was opened for
412 * writing i.e. vma may be mprotected writable even if now readonly.
413 */
414static inline int mapping_writably_mapped(struct address_space *mapping)
415{
416 return mapping->i_mmap_writable != 0;
417}
418
419/*
420 * Use sequence counter to get consistent i_size on 32-bit processors.
421 */
422#if BITS_PER_LONG==32 && defined(CONFIG_SMP)
423#include <linux/seqlock.h>
424#define __NEED_I_SIZE_ORDERED
425#define i_size_ordered_init(inode) seqcount_init(&inode->i_size_seqcount)
426#else
427#define i_size_ordered_init(inode) do { } while (0)
428#endif
429
430struct inode {
431 struct hlist_node i_hash;
432 struct list_head i_list;
433 struct list_head i_sb_list;
434 struct list_head i_dentry;
435 unsigned long i_ino;
436 atomic_t i_count;
437 umode_t i_mode;
438 unsigned int i_nlink;
439 uid_t i_uid;
440 gid_t i_gid;
441 dev_t i_rdev;
442 loff_t i_size;
443 struct timespec i_atime;
444 struct timespec i_mtime;
445 struct timespec i_ctime;
446 unsigned int i_blkbits;
447 unsigned long i_blksize;
448 unsigned long i_version;
449 unsigned long i_blocks;
450 unsigned short i_bytes;
451 spinlock_t i_lock; /* i_blocks, i_bytes, maybe i_size */
452 struct semaphore i_sem;
453 struct rw_semaphore i_alloc_sem;
454 struct inode_operations *i_op;
455 struct file_operations *i_fop; /* former ->i_op->default_file_ops */
456 struct super_block *i_sb;
457 struct file_lock *i_flock;
458 struct address_space *i_mapping;
459 struct address_space i_data;
460#ifdef CONFIG_QUOTA
461 struct dquot *i_dquot[MAXQUOTAS];
462#endif
463 /* These three should probably be a union */
464 struct list_head i_devices;
465 struct pipe_inode_info *i_pipe;
466 struct block_device *i_bdev;
467 struct cdev *i_cdev;
468 int i_cindex;
469
470 __u32 i_generation;
471
472#ifdef CONFIG_DNOTIFY
473 unsigned long i_dnotify_mask; /* Directory notify events */
474 struct dnotify_struct *i_dnotify; /* for directory notifications */
475#endif
476
477 unsigned long i_state;
478 unsigned long dirtied_when; /* jiffies of first dirtying */
479
480 unsigned int i_flags;
481
482 atomic_t i_writecount;
483 void *i_security;
484 union {
485 void *generic_ip;
486 } u;
487#ifdef __NEED_I_SIZE_ORDERED
488 seqcount_t i_size_seqcount;
489#endif
490};
491
492/*
493 * NOTE: in a 32bit arch with a preemptable kernel and
494 * an UP compile the i_size_read/write must be atomic
495 * with respect to the local cpu (unlike with preempt disabled),
496 * but they don't need to be atomic with respect to other cpus like in
497 * true SMP (so they need either to either locally disable irq around
498 * the read or for example on x86 they can be still implemented as a
499 * cmpxchg8b without the need of the lock prefix). For SMP compiles
500 * and 64bit archs it makes no difference if preempt is enabled or not.
501 */
502static inline loff_t i_size_read(struct inode *inode)
503{
504#if BITS_PER_LONG==32 && defined(CONFIG_SMP)
505 loff_t i_size;
506 unsigned int seq;
507
508 do {
509 seq = read_seqcount_begin(&inode->i_size_seqcount);
510 i_size = inode->i_size;
511 } while (read_seqcount_retry(&inode->i_size_seqcount, seq));
512 return i_size;
513#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT)
514 loff_t i_size;
515
516 preempt_disable();
517 i_size = inode->i_size;
518 preempt_enable();
519 return i_size;
520#else
521 return inode->i_size;
522#endif
523}
524
525
526static inline void i_size_write(struct inode *inode, loff_t i_size)
527{
528#if BITS_PER_LONG==32 && defined(CONFIG_SMP)
529 write_seqcount_begin(&inode->i_size_seqcount);
530 inode->i_size = i_size;
531 write_seqcount_end(&inode->i_size_seqcount);
532#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT)
533 preempt_disable();
534 inode->i_size = i_size;
535 preempt_enable();
536#else
537 inode->i_size = i_size;
538#endif
539}
540
541static inline unsigned iminor(struct inode *inode)
542{
543 return MINOR(inode->i_rdev);
544}
545
546static inline unsigned imajor(struct inode *inode)
547{
548 return MAJOR(inode->i_rdev);
549}
550
551extern struct block_device *I_BDEV(struct inode *inode);
552
553struct fown_struct {
554 rwlock_t lock; /* protects pid, uid, euid fields */
555 int pid; /* pid or -pgrp where SIGIO should be sent */
556 uid_t uid, euid; /* uid/euid of process setting the owner */
557 void *security;
558 int signum; /* posix.1b rt signal to be delivered on IO */
559};
560
561/*
562 * Track a single file's readahead state
563 */
564struct file_ra_state {
565 unsigned long start; /* Current window */
566 unsigned long size;
567 unsigned long flags; /* ra flags RA_FLAG_xxx*/
568 unsigned long cache_hit; /* cache hit count*/
569 unsigned long prev_page; /* Cache last read() position */
570 unsigned long ahead_start; /* Ahead window */
571 unsigned long ahead_size;
572 unsigned long ra_pages; /* Maximum readahead window */
573 unsigned long mmap_hit; /* Cache hit stat for mmap accesses */
574 unsigned long mmap_miss; /* Cache miss stat for mmap accesses */
575};
576#define RA_FLAG_MISS 0x01 /* a cache miss occured against this file */
577#define RA_FLAG_INCACHE 0x02 /* file is already in cache */
578
579struct file {
580 struct list_head f_list;
581 struct dentry *f_dentry;
582 struct vfsmount *f_vfsmnt;
583 struct file_operations *f_op;
584 atomic_t f_count;
585 unsigned int f_flags;
586 mode_t f_mode;
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587 loff_t f_pos;
588 struct fown_struct f_owner;
589 unsigned int f_uid, f_gid;
590 struct file_ra_state f_ra;
591
592 size_t f_maxcount;
593 unsigned long f_version;
594 void *f_security;
595
596 /* needed for tty driver, and maybe others */
597 void *private_data;
598
599#ifdef CONFIG_EPOLL
600 /* Used by fs/eventpoll.c to link all the hooks to this file */
601 struct list_head f_ep_links;
602 spinlock_t f_ep_lock;
603#endif /* #ifdef CONFIG_EPOLL */
604 struct address_space *f_mapping;
605};
606extern spinlock_t files_lock;
607#define file_list_lock() spin_lock(&files_lock);
608#define file_list_unlock() spin_unlock(&files_lock);
609
610#define get_file(x) atomic_inc(&(x)->f_count)
611#define file_count(x) atomic_read(&(x)->f_count)
612
613#define MAX_NON_LFS ((1UL<<31) - 1)
614
615/* Page cache limit. The filesystems should put that into their s_maxbytes
616 limits, otherwise bad things can happen in VM. */
617#if BITS_PER_LONG==32
618#define MAX_LFS_FILESIZE (((u64)PAGE_CACHE_SIZE << (BITS_PER_LONG-1))-1)
619#elif BITS_PER_LONG==64
620#define MAX_LFS_FILESIZE 0x7fffffffffffffffUL
621#endif
622
623#define FL_POSIX 1
624#define FL_FLOCK 2
625#define FL_ACCESS 8 /* not trying to lock, just looking */
626#define FL_LOCKD 16 /* lock held by rpc.lockd */
627#define FL_LEASE 32 /* lease held on this file */
628#define FL_SLEEP 128 /* A blocking lock */
629
630/*
631 * The POSIX file lock owner is determined by
632 * the "struct files_struct" in the thread group
633 * (or NULL for no owner - BSD locks).
634 *
635 * Lockd stuffs a "host" pointer into this.
636 */
637typedef struct files_struct *fl_owner_t;
638
639struct file_lock_operations {
640 void (*fl_insert)(struct file_lock *); /* lock insertion callback */
641 void (*fl_remove)(struct file_lock *); /* lock removal callback */
642 void (*fl_copy_lock)(struct file_lock *, struct file_lock *);
643 void (*fl_release_private)(struct file_lock *);
644};
645
646struct lock_manager_operations {
647 int (*fl_compare_owner)(struct file_lock *, struct file_lock *);
648 void (*fl_notify)(struct file_lock *); /* unblock callback */
649 void (*fl_copy_lock)(struct file_lock *, struct file_lock *);
650 void (*fl_release_private)(struct file_lock *);
651 void (*fl_break)(struct file_lock *);
652 int (*fl_mylease)(struct file_lock *, struct file_lock *);
653 int (*fl_change)(struct file_lock **, int);
654};
655
656/* that will die - we need it for nfs_lock_info */
657#include <linux/nfs_fs_i.h>
658
659struct file_lock {
660 struct file_lock *fl_next; /* singly linked list for this inode */
661 struct list_head fl_link; /* doubly linked list of all locks */
662 struct list_head fl_block; /* circular list of blocked processes */
663 fl_owner_t fl_owner;
664 unsigned int fl_pid;
665 wait_queue_head_t fl_wait;
666 struct file *fl_file;
667 unsigned char fl_flags;
668 unsigned char fl_type;
669 loff_t fl_start;
670 loff_t fl_end;
671
672 struct fasync_struct * fl_fasync; /* for lease break notifications */
673 unsigned long fl_break_time; /* for nonblocking lease breaks */
674
675 struct file_lock_operations *fl_ops; /* Callbacks for filesystems */
676 struct lock_manager_operations *fl_lmops; /* Callbacks for lockmanagers */
677 union {
678 struct nfs_lock_info nfs_fl;
8d0a8a9d 679 struct nfs4_lock_info nfs4_fl;
1da177e4
LT
680 } fl_u;
681};
682
683/* The following constant reflects the upper bound of the file/locking space */
684#ifndef OFFSET_MAX
685#define INT_LIMIT(x) (~((x)1 << (sizeof(x)*8 - 1)))
686#define OFFSET_MAX INT_LIMIT(loff_t)
687#define OFFT_OFFSET_MAX INT_LIMIT(off_t)
688#endif
689
690extern struct list_head file_lock_list;
691
692#include <linux/fcntl.h>
693
694extern int fcntl_getlk(struct file *, struct flock __user *);
695extern int fcntl_setlk(struct file *, unsigned int, struct flock __user *);
696
697#if BITS_PER_LONG == 32
698extern int fcntl_getlk64(struct file *, struct flock64 __user *);
699extern int fcntl_setlk64(struct file *, unsigned int, struct flock64 __user *);
700#endif
701
702extern void send_sigio(struct fown_struct *fown, int fd, int band);
703extern int fcntl_setlease(unsigned int fd, struct file *filp, long arg);
704extern int fcntl_getlease(struct file *filp);
705
706/* fs/locks.c */
707extern void locks_init_lock(struct file_lock *);
708extern void locks_copy_lock(struct file_lock *, struct file_lock *);
709extern void locks_remove_posix(struct file *, fl_owner_t);
710extern void locks_remove_flock(struct file *);
711extern struct file_lock *posix_test_lock(struct file *, struct file_lock *);
712extern int posix_lock_file(struct file *, struct file_lock *);
713extern int posix_lock_file_wait(struct file *, struct file_lock *);
714extern void posix_block_lock(struct file_lock *, struct file_lock *);
715extern void posix_unblock_lock(struct file *, struct file_lock *);
716extern int posix_locks_deadlock(struct file_lock *, struct file_lock *);
717extern int flock_lock_file_wait(struct file *filp, struct file_lock *fl);
718extern int __break_lease(struct inode *inode, unsigned int flags);
719extern void lease_get_mtime(struct inode *, struct timespec *time);
720extern int setlease(struct file *, long, struct file_lock **);
721extern int lease_modify(struct file_lock **, int);
722extern int lock_may_read(struct inode *, loff_t start, unsigned long count);
723extern int lock_may_write(struct inode *, loff_t start, unsigned long count);
724extern void steal_locks(fl_owner_t from);
725
726struct fasync_struct {
727 int magic;
728 int fa_fd;
729 struct fasync_struct *fa_next; /* singly linked list */
730 struct file *fa_file;
731};
732
733#define FASYNC_MAGIC 0x4601
734
735/* SMP safe fasync helpers: */
736extern int fasync_helper(int, struct file *, int, struct fasync_struct **);
737/* can be called from interrupts */
738extern void kill_fasync(struct fasync_struct **, int, int);
739/* only for net: no internal synchronization */
740extern void __kill_fasync(struct fasync_struct *, int, int);
741
742extern int f_setown(struct file *filp, unsigned long arg, int force);
743extern void f_delown(struct file *filp);
744extern int send_sigurg(struct fown_struct *fown);
745
746/*
747 * Umount options
748 */
749
750#define MNT_FORCE 0x00000001 /* Attempt to forcibily umount */
751#define MNT_DETACH 0x00000002 /* Just detach from the tree */
752#define MNT_EXPIRE 0x00000004 /* Mark for expiry */
753
754extern struct list_head super_blocks;
755extern spinlock_t sb_lock;
756
757#define sb_entry(list) list_entry((list), struct super_block, s_list)
758#define S_BIAS (1<<30)
759struct super_block {
760 struct list_head s_list; /* Keep this first */
761 dev_t s_dev; /* search index; _not_ kdev_t */
762 unsigned long s_blocksize;
763 unsigned long s_old_blocksize;
764 unsigned char s_blocksize_bits;
765 unsigned char s_dirt;
766 unsigned long long s_maxbytes; /* Max file size */
767 struct file_system_type *s_type;
768 struct super_operations *s_op;
769 struct dquot_operations *dq_op;
770 struct quotactl_ops *s_qcop;
771 struct export_operations *s_export_op;
772 unsigned long s_flags;
773 unsigned long s_magic;
774 struct dentry *s_root;
775 struct rw_semaphore s_umount;
776 struct semaphore s_lock;
777 int s_count;
778 int s_syncing;
779 int s_need_sync_fs;
780 atomic_t s_active;
781 void *s_security;
782 struct xattr_handler **s_xattr;
783
784 struct list_head s_inodes; /* all inodes */
785 struct list_head s_dirty; /* dirty inodes */
786 struct list_head s_io; /* parked for writeback */
787 struct hlist_head s_anon; /* anonymous dentries for (nfs) exporting */
788 struct list_head s_files;
789
790 struct block_device *s_bdev;
791 struct list_head s_instances;
792 struct quota_info s_dquot; /* Diskquota specific options */
793
794 int s_frozen;
795 wait_queue_head_t s_wait_unfrozen;
796
797 char s_id[32]; /* Informational name */
798
799 void *s_fs_info; /* Filesystem private info */
800
801 /*
802 * The next field is for VFS *only*. No filesystems have any business
803 * even looking at it. You had been warned.
804 */
805 struct semaphore s_vfs_rename_sem; /* Kludge */
806
807 /* Granuality of c/m/atime in ns.
808 Cannot be worse than a second */
809 u32 s_time_gran;
810};
811
812extern struct timespec current_fs_time(struct super_block *sb);
813
814/*
815 * Snapshotting support.
816 */
817enum {
818 SB_UNFROZEN = 0,
819 SB_FREEZE_WRITE = 1,
820 SB_FREEZE_TRANS = 2,
821};
822
823#define vfs_check_frozen(sb, level) \
824 wait_event((sb)->s_wait_unfrozen, ((sb)->s_frozen < (level)))
825
22e2c507
JA
826static inline void get_fs_excl(void)
827{
828 atomic_inc(&current->fs_excl);
829}
830
831static inline void put_fs_excl(void)
832{
833 atomic_dec(&current->fs_excl);
834}
835
836static inline int has_fs_excl(void)
837{
838 return atomic_read(&current->fs_excl);
839}
840
841
1da177e4
LT
842/*
843 * Superblock locking.
844 */
845static inline void lock_super(struct super_block * sb)
846{
22e2c507 847 get_fs_excl();
1da177e4
LT
848 down(&sb->s_lock);
849}
850
851static inline void unlock_super(struct super_block * sb)
852{
22e2c507 853 put_fs_excl();
1da177e4
LT
854 up(&sb->s_lock);
855}
856
857/*
858 * VFS helper functions..
859 */
860extern int vfs_create(struct inode *, struct dentry *, int, struct nameidata *);
861extern int vfs_mkdir(struct inode *, struct dentry *, int);
862extern int vfs_mknod(struct inode *, struct dentry *, int, dev_t);
863extern int vfs_symlink(struct inode *, struct dentry *, const char *, int);
864extern int vfs_link(struct dentry *, struct inode *, struct dentry *);
865extern int vfs_rmdir(struct inode *, struct dentry *);
866extern int vfs_unlink(struct inode *, struct dentry *);
867extern int vfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *);
868
869/*
870 * VFS dentry helper functions.
871 */
872extern void dentry_unhash(struct dentry *dentry);
873
874/*
875 * File types
876 *
877 * NOTE! These match bits 12..15 of stat.st_mode
878 * (ie "(i_mode >> 12) & 15").
879 */
880#define DT_UNKNOWN 0
881#define DT_FIFO 1
882#define DT_CHR 2
883#define DT_DIR 4
884#define DT_BLK 6
885#define DT_REG 8
886#define DT_LNK 10
887#define DT_SOCK 12
888#define DT_WHT 14
889
890#define OSYNC_METADATA (1<<0)
891#define OSYNC_DATA (1<<1)
892#define OSYNC_INODE (1<<2)
893int generic_osync_inode(struct inode *, struct address_space *, int);
894
895/*
896 * This is the "filldir" function type, used by readdir() to let
897 * the kernel specify what kind of dirent layout it wants to have.
898 * This allows the kernel to read directories into kernel space or
899 * to have different dirent layouts depending on the binary type.
900 */
901typedef int (*filldir_t)(void *, const char *, int, loff_t, ino_t, unsigned);
902
903struct block_device_operations {
904 int (*open) (struct inode *, struct file *);
905 int (*release) (struct inode *, struct file *);
906 int (*ioctl) (struct inode *, struct file *, unsigned, unsigned long);
bb93e3a5 907 long (*unlocked_ioctl) (struct file *, unsigned, unsigned long);
1da177e4 908 long (*compat_ioctl) (struct file *, unsigned, unsigned long);
420edbcc 909 int (*direct_access) (struct block_device *, sector_t, unsigned long *);
1da177e4
LT
910 int (*media_changed) (struct gendisk *);
911 int (*revalidate_disk) (struct gendisk *);
912 struct module *owner;
913};
914
915/*
916 * "descriptor" for what we're up to with a read for sendfile().
917 * This allows us to use the same read code yet
918 * have multiple different users of the data that
919 * we read from a file.
920 *
921 * The simplest case just copies the data to user
922 * mode.
923 */
924typedef struct {
925 size_t written;
926 size_t count;
927 union {
928 char __user * buf;
929 void *data;
930 } arg;
931 int error;
932} read_descriptor_t;
933
934typedef int (*read_actor_t)(read_descriptor_t *, struct page *, unsigned long, unsigned long);
935
936/* These macros are for out of kernel modules to test that
937 * the kernel supports the unlocked_ioctl and compat_ioctl
938 * fields in struct file_operations. */
939#define HAVE_COMPAT_IOCTL 1
940#define HAVE_UNLOCKED_IOCTL 1
941
942/*
943 * NOTE:
944 * read, write, poll, fsync, readv, writev, unlocked_ioctl and compat_ioctl
945 * can be called without the big kernel lock held in all filesystems.
946 */
947struct file_operations {
948 struct module *owner;
949 loff_t (*llseek) (struct file *, loff_t, int);
950 ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
951 ssize_t (*aio_read) (struct kiocb *, char __user *, size_t, loff_t);
952 ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
953 ssize_t (*aio_write) (struct kiocb *, const char __user *, size_t, loff_t);
954 int (*readdir) (struct file *, void *, filldir_t);
955 unsigned int (*poll) (struct file *, struct poll_table_struct *);
956 int (*ioctl) (struct inode *, struct file *, unsigned int, unsigned long);
957 long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
958 long (*compat_ioctl) (struct file *, unsigned int, unsigned long);
959 int (*mmap) (struct file *, struct vm_area_struct *);
960 int (*open) (struct inode *, struct file *);
961 int (*flush) (struct file *);
962 int (*release) (struct inode *, struct file *);
963 int (*fsync) (struct file *, struct dentry *, int datasync);
964 int (*aio_fsync) (struct kiocb *, int datasync);
965 int (*fasync) (int, struct file *, int);
966 int (*lock) (struct file *, int, struct file_lock *);
967 ssize_t (*readv) (struct file *, const struct iovec *, unsigned long, loff_t *);
968 ssize_t (*writev) (struct file *, const struct iovec *, unsigned long, loff_t *);
969 ssize_t (*sendfile) (struct file *, loff_t *, size_t, read_actor_t, void *);
970 ssize_t (*sendpage) (struct file *, struct page *, int, size_t, loff_t *, int);
971 unsigned long (*get_unmapped_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
972 int (*check_flags)(int);
973 int (*dir_notify)(struct file *filp, unsigned long arg);
974 int (*flock) (struct file *, int, struct file_lock *);
975};
976
977struct inode_operations {
978 int (*create) (struct inode *,struct dentry *,int, struct nameidata *);
979 struct dentry * (*lookup) (struct inode *,struct dentry *, struct nameidata *);
980 int (*link) (struct dentry *,struct inode *,struct dentry *);
981 int (*unlink) (struct inode *,struct dentry *);
982 int (*symlink) (struct inode *,struct dentry *,const char *);
983 int (*mkdir) (struct inode *,struct dentry *,int);
984 int (*rmdir) (struct inode *,struct dentry *);
985 int (*mknod) (struct inode *,struct dentry *,int,dev_t);
986 int (*rename) (struct inode *, struct dentry *,
987 struct inode *, struct dentry *);
988 int (*readlink) (struct dentry *, char __user *,int);
989 int (*follow_link) (struct dentry *, struct nameidata *);
990 void (*put_link) (struct dentry *, struct nameidata *);
991 void (*truncate) (struct inode *);
992 int (*permission) (struct inode *, int, struct nameidata *);
993 int (*setattr) (struct dentry *, struct iattr *);
994 int (*getattr) (struct vfsmount *mnt, struct dentry *, struct kstat *);
995 int (*setxattr) (struct dentry *, const char *,const void *,size_t,int);
996 ssize_t (*getxattr) (struct dentry *, const char *, void *, size_t);
997 ssize_t (*listxattr) (struct dentry *, char *, size_t);
998 int (*removexattr) (struct dentry *, const char *);
999};
1000
1001struct seq_file;
1002
1003extern ssize_t vfs_read(struct file *, char __user *, size_t, loff_t *);
1004extern ssize_t vfs_write(struct file *, const char __user *, size_t, loff_t *);
1005extern ssize_t vfs_readv(struct file *, const struct iovec __user *,
1006 unsigned long, loff_t *);
1007extern ssize_t vfs_writev(struct file *, const struct iovec __user *,
1008 unsigned long, loff_t *);
1009
1010/*
1011 * NOTE: write_inode, delete_inode, clear_inode, put_inode can be called
1012 * without the big kernel lock held in all filesystems.
1013 */
1014struct super_operations {
1015 struct inode *(*alloc_inode)(struct super_block *sb);
1016 void (*destroy_inode)(struct inode *);
1017
1018 void (*read_inode) (struct inode *);
1019
1020 void (*dirty_inode) (struct inode *);
1021 int (*write_inode) (struct inode *, int);
1022 void (*put_inode) (struct inode *);
1023 void (*drop_inode) (struct inode *);
1024 void (*delete_inode) (struct inode *);
1025 void (*put_super) (struct super_block *);
1026 void (*write_super) (struct super_block *);
1027 int (*sync_fs)(struct super_block *sb, int wait);
1028 void (*write_super_lockfs) (struct super_block *);
1029 void (*unlockfs) (struct super_block *);
1030 int (*statfs) (struct super_block *, struct kstatfs *);
1031 int (*remount_fs) (struct super_block *, int *, char *);
1032 void (*clear_inode) (struct inode *);
1033 void (*umount_begin) (struct super_block *);
1034
1035 int (*show_options)(struct seq_file *, struct vfsmount *);
1036
1037 ssize_t (*quota_read)(struct super_block *, int, char *, size_t, loff_t);
1038 ssize_t (*quota_write)(struct super_block *, int, const char *, size_t, loff_t);
1039};
1040
1041/* Inode state bits. Protected by inode_lock. */
1042#define I_DIRTY_SYNC 1 /* Not dirty enough for O_DATASYNC */
1043#define I_DIRTY_DATASYNC 2 /* Data-related inode changes pending */
1044#define I_DIRTY_PAGES 4 /* Data-related inode changes pending */
1045#define __I_LOCK 3
1046#define I_LOCK (1 << __I_LOCK)
1047#define I_FREEING 16
1048#define I_CLEAR 32
1049#define I_NEW 64
991114c6 1050#define I_WILL_FREE 128
1da177e4
LT
1051
1052#define I_DIRTY (I_DIRTY_SYNC | I_DIRTY_DATASYNC | I_DIRTY_PAGES)
1053
1054extern void __mark_inode_dirty(struct inode *, int);
1055static inline void mark_inode_dirty(struct inode *inode)
1056{
1057 __mark_inode_dirty(inode, I_DIRTY);
1058}
1059
1060static inline void mark_inode_dirty_sync(struct inode *inode)
1061{
1062 __mark_inode_dirty(inode, I_DIRTY_SYNC);
1063}
1064
1065static inline void touch_atime(struct vfsmount *mnt, struct dentry *dentry)
1066{
1067 /* per-mountpoint checks will go here */
1068 update_atime(dentry->d_inode);
1069}
1070
1071static inline void file_accessed(struct file *file)
1072{
1073 if (!(file->f_flags & O_NOATIME))
1074 touch_atime(file->f_vfsmnt, file->f_dentry);
1075}
1076
1077int sync_inode(struct inode *inode, struct writeback_control *wbc);
1078
1079/**
4dc3b16b
PP
1080 * struct export_operations - for nfsd to communicate with file systems
1081 * @decode_fh: decode a file handle fragment and return a &struct dentry
1082 * @encode_fh: encode a file handle fragment from a dentry
1083 * @get_name: find the name for a given inode in a given directory
1084 * @get_parent: find the parent of a given directory
1085 * @get_dentry: find a dentry for the inode given a file handle sub-fragment
1da177e4
LT
1086 *
1087 * Description:
1088 * The export_operations structure provides a means for nfsd to communicate
1089 * with a particular exported file system - particularly enabling nfsd and
1090 * the filesystem to co-operate when dealing with file handles.
1091 *
67be2dd1
MW
1092 * export_operations contains two basic operation for dealing with file
1093 * handles, decode_fh() and encode_fh(), and allows for some other
1094 * operations to be defined which standard helper routines use to get
1095 * specific information from the filesystem.
1da177e4
LT
1096 *
1097 * nfsd encodes information use to determine which filesystem a filehandle
67be2dd1
MW
1098 * applies to in the initial part of the file handle. The remainder, termed
1099 * a file handle fragment, is controlled completely by the filesystem. The
1100 * standard helper routines assume that this fragment will contain one or
1101 * two sub-fragments, one which identifies the file, and one which may be
1102 * used to identify the (a) directory containing the file.
1da177e4
LT
1103 *
1104 * In some situations, nfsd needs to get a dentry which is connected into a
67be2dd1
MW
1105 * specific part of the file tree. To allow for this, it passes the
1106 * function acceptable() together with a @context which can be used to see
1107 * if the dentry is acceptable. As there can be multiple dentrys for a
1108 * given file, the filesystem should check each one for acceptability before
1109 * looking for the next. As soon as an acceptable one is found, it should
1110 * be returned.
1da177e4
LT
1111 *
1112 * decode_fh:
67be2dd1
MW
1113 * @decode_fh is given a &struct super_block (@sb), a file handle fragment
1114 * (@fh, @fh_len) and an acceptability testing function (@acceptable,
1115 * @context). It should return a &struct dentry which refers to the same
1116 * file that the file handle fragment refers to, and which passes the
1117 * acceptability test. If it cannot, it should return a %NULL pointer if
1118 * the file was found but no acceptable &dentries were available, or a
1119 * %ERR_PTR error code indicating why it couldn't be found (e.g. %ENOENT or
1120 * %ENOMEM).
1da177e4
LT
1121 *
1122 * encode_fh:
67be2dd1
MW
1123 * @encode_fh should store in the file handle fragment @fh (using at most
1124 * @max_len bytes) information that can be used by @decode_fh to recover the
1125 * file refered to by the &struct dentry @de. If the @connectable flag is
1126 * set, the encode_fh() should store sufficient information so that a good
1127 * attempt can be made to find not only the file but also it's place in the
1128 * filesystem. This typically means storing a reference to de->d_parent in
1129 * the filehandle fragment. encode_fh() should return the number of bytes
1130 * stored or a negative error code such as %-ENOSPC
1da177e4
LT
1131 *
1132 * get_name:
67be2dd1
MW
1133 * @get_name should find a name for the given @child in the given @parent
1134 * directory. The name should be stored in the @name (with the
1135 * understanding that it is already pointing to a a %NAME_MAX+1 sized
1136 * buffer. get_name() should return %0 on success, a negative error code
1137 * or error. @get_name will be called without @parent->i_sem held.
1da177e4
LT
1138 *
1139 * get_parent:
67be2dd1
MW
1140 * @get_parent should find the parent directory for the given @child which
1141 * is also a directory. In the event that it cannot be found, or storage
1142 * space cannot be allocated, a %ERR_PTR should be returned.
1da177e4
LT
1143 *
1144 * get_dentry:
67be2dd1
MW
1145 * Given a &super_block (@sb) and a pointer to a file-system specific inode
1146 * identifier, possibly an inode number, (@inump) get_dentry() should find
1147 * the identified inode and return a dentry for that inode. Any suitable
1148 * dentry can be returned including, if necessary, a new dentry created with
1149 * d_alloc_root. The caller can then find any other extant dentrys by
1150 * following the d_alias links. If a new dentry was created using
1151 * d_alloc_root, DCACHE_NFSD_DISCONNECTED should be set, and the dentry
1152 * should be d_rehash()ed.
1da177e4 1153 *
67be2dd1
MW
1154 * If the inode cannot be found, either a %NULL pointer or an %ERR_PTR code
1155 * can be returned. The @inump will be whatever was passed to
1156 * nfsd_find_fh_dentry() in either the @obj or @parent parameters.
1da177e4
LT
1157 *
1158 * Locking rules:
67be2dd1
MW
1159 * get_parent is called with child->d_inode->i_sem down
1160 * get_name is not (which is possibly inconsistent)
1da177e4
LT
1161 */
1162
1163struct export_operations {
1164 struct dentry *(*decode_fh)(struct super_block *sb, __u32 *fh, int fh_len, int fh_type,
1165 int (*acceptable)(void *context, struct dentry *de),
1166 void *context);
1167 int (*encode_fh)(struct dentry *de, __u32 *fh, int *max_len,
1168 int connectable);
1169
1170 /* the following are only called from the filesystem itself */
1171 int (*get_name)(struct dentry *parent, char *name,
1172 struct dentry *child);
1173 struct dentry * (*get_parent)(struct dentry *child);
1174 struct dentry * (*get_dentry)(struct super_block *sb, void *inump);
1175
1176 /* This is set by the exporting module to a standard helper */
1177 struct dentry * (*find_exported_dentry)(
1178 struct super_block *sb, void *obj, void *parent,
1179 int (*acceptable)(void *context, struct dentry *de),
1180 void *context);
1181
1182
1183};
1184
1185extern struct dentry *
1186find_exported_dentry(struct super_block *sb, void *obj, void *parent,
1187 int (*acceptable)(void *context, struct dentry *de),
1188 void *context);
1189
1190struct file_system_type {
1191 const char *name;
1192 int fs_flags;
1193 struct super_block *(*get_sb) (struct file_system_type *, int,
1194 const char *, void *);
1195 void (*kill_sb) (struct super_block *);
1196 struct module *owner;
1197 struct file_system_type * next;
1198 struct list_head fs_supers;
1199};
1200
1201struct super_block *get_sb_bdev(struct file_system_type *fs_type,
1202 int flags, const char *dev_name, void *data,
1203 int (*fill_super)(struct super_block *, void *, int));
1204struct super_block *get_sb_single(struct file_system_type *fs_type,
1205 int flags, void *data,
1206 int (*fill_super)(struct super_block *, void *, int));
1207struct super_block *get_sb_nodev(struct file_system_type *fs_type,
1208 int flags, void *data,
1209 int (*fill_super)(struct super_block *, void *, int));
1210void generic_shutdown_super(struct super_block *sb);
1211void kill_block_super(struct super_block *sb);
1212void kill_anon_super(struct super_block *sb);
1213void kill_litter_super(struct super_block *sb);
1214void deactivate_super(struct super_block *sb);
1215int set_anon_super(struct super_block *s, void *data);
1216struct super_block *sget(struct file_system_type *type,
1217 int (*test)(struct super_block *,void *),
1218 int (*set)(struct super_block *,void *),
1219 void *data);
1220struct super_block *get_sb_pseudo(struct file_system_type *, char *,
1221 struct super_operations *ops, unsigned long);
1222int __put_super(struct super_block *sb);
1223int __put_super_and_need_restart(struct super_block *sb);
1224void unnamed_dev_init(void);
1225
1226/* Alas, no aliases. Too much hassle with bringing module.h everywhere */
1227#define fops_get(fops) \
1228 (((fops) && try_module_get((fops)->owner) ? (fops) : NULL))
1229#define fops_put(fops) \
1230 do { if (fops) module_put((fops)->owner); } while(0)
1231
1232extern int register_filesystem(struct file_system_type *);
1233extern int unregister_filesystem(struct file_system_type *);
1234extern struct vfsmount *kern_mount(struct file_system_type *);
1235extern int may_umount_tree(struct vfsmount *);
1236extern int may_umount(struct vfsmount *);
1237extern long do_mount(char *, char *, char *, unsigned long, void *);
1238
1239extern int vfs_statfs(struct super_block *, struct kstatfs *);
1240
1241#define FLOCK_VERIFY_READ 1
1242#define FLOCK_VERIFY_WRITE 2
1243
1244extern int locks_mandatory_locked(struct inode *);
1245extern int locks_mandatory_area(int, struct inode *, struct file *, loff_t, size_t);
1246
1247/*
1248 * Candidates for mandatory locking have the setgid bit set
1249 * but no group execute bit - an otherwise meaningless combination.
1250 */
1251#define MANDATORY_LOCK(inode) \
1252 (IS_MANDLOCK(inode) && ((inode)->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID)
1253
1254static inline int locks_verify_locked(struct inode *inode)
1255{
1256 if (MANDATORY_LOCK(inode))
1257 return locks_mandatory_locked(inode);
1258 return 0;
1259}
1260
1261extern int rw_verify_area(int, struct file *, loff_t *, size_t);
1262
1263static inline int locks_verify_truncate(struct inode *inode,
1264 struct file *filp,
1265 loff_t size)
1266{
1267 if (inode->i_flock && MANDATORY_LOCK(inode))
1268 return locks_mandatory_area(
1269 FLOCK_VERIFY_WRITE, inode, filp,
1270 size < inode->i_size ? size : inode->i_size,
1271 (size < inode->i_size ? inode->i_size - size
1272 : size - inode->i_size)
1273 );
1274 return 0;
1275}
1276
1277static inline int break_lease(struct inode *inode, unsigned int mode)
1278{
1279 if (inode->i_flock)
1280 return __break_lease(inode, mode);
1281 return 0;
1282}
1283
1284/* fs/open.c */
1285
1286extern int do_truncate(struct dentry *, loff_t start);
1287extern struct file *filp_open(const char *, int, int);
1288extern struct file * dentry_open(struct dentry *, struct vfsmount *, int);
1289extern int filp_close(struct file *, fl_owner_t id);
1290extern char * getname(const char __user *);
1291
1292/* fs/dcache.c */
1293extern void __init vfs_caches_init_early(void);
1294extern void __init vfs_caches_init(unsigned long);
1295
1296#define __getname() kmem_cache_alloc(names_cachep, SLAB_KERNEL)
1297#define __putname(name) kmem_cache_free(names_cachep, (void *)(name))
1298#ifndef CONFIG_AUDITSYSCALL
1299#define putname(name) __putname(name)
1300#else
1301extern void putname(const char *name);
1302#endif
1303
1304extern int register_blkdev(unsigned int, const char *);
1305extern int unregister_blkdev(unsigned int, const char *);
1306extern struct block_device *bdget(dev_t);
1307extern void bd_set_size(struct block_device *, loff_t size);
1308extern void bd_forget(struct inode *inode);
1309extern void bdput(struct block_device *);
1310extern struct block_device *open_by_devnum(dev_t, unsigned);
1311extern struct file_operations def_blk_fops;
1312extern struct address_space_operations def_blk_aops;
1313extern struct file_operations def_chr_fops;
1314extern struct file_operations bad_sock_fops;
1315extern struct file_operations def_fifo_fops;
1316extern int ioctl_by_bdev(struct block_device *, unsigned, unsigned long);
1317extern int blkdev_ioctl(struct inode *, struct file *, unsigned, unsigned long);
1318extern long compat_blkdev_ioctl(struct file *, unsigned, unsigned long);
1319extern int blkdev_get(struct block_device *, mode_t, unsigned);
1320extern int blkdev_put(struct block_device *);
1321extern int bd_claim(struct block_device *, void *);
1322extern void bd_release(struct block_device *);
1323
1324/* fs/char_dev.c */
1325extern int alloc_chrdev_region(dev_t *, unsigned, unsigned, const char *);
1326extern int register_chrdev_region(dev_t, unsigned, const char *);
1327extern int register_chrdev(unsigned int, const char *,
1328 struct file_operations *);
1329extern int unregister_chrdev(unsigned int, const char *);
1330extern void unregister_chrdev_region(dev_t, unsigned);
1331extern int chrdev_open(struct inode *, struct file *);
1332
1333/* fs/block_dev.c */
1334#define BDEVNAME_SIZE 32 /* Largest string for a blockdev identifier */
1335extern const char *__bdevname(dev_t, char *buffer);
1336extern const char *bdevname(struct block_device *bdev, char *buffer);
1337extern struct block_device *lookup_bdev(const char *);
1338extern struct block_device *open_bdev_excl(const char *, int, void *);
1339extern void close_bdev_excl(struct block_device *);
1340
1341extern void init_special_inode(struct inode *, umode_t, dev_t);
1342
1343/* Invalid inode operations -- fs/bad_inode.c */
1344extern void make_bad_inode(struct inode *);
1345extern int is_bad_inode(struct inode *);
1346
1347extern struct file_operations read_fifo_fops;
1348extern struct file_operations write_fifo_fops;
1349extern struct file_operations rdwr_fifo_fops;
1350extern struct file_operations read_pipe_fops;
1351extern struct file_operations write_pipe_fops;
1352extern struct file_operations rdwr_pipe_fops;
1353
1354extern int fs_may_remount_ro(struct super_block *);
1355
1356/*
1357 * return READ, READA, or WRITE
1358 */
1359#define bio_rw(bio) ((bio)->bi_rw & (RW_MASK | RWA_MASK))
1360
1361/*
1362 * return data direction, READ or WRITE
1363 */
1364#define bio_data_dir(bio) ((bio)->bi_rw & 1)
1365
1366extern int check_disk_change(struct block_device *);
1367extern int invalidate_inodes(struct super_block *);
2ef41634 1368extern int __invalidate_device(struct block_device *);
1da177e4
LT
1369extern int invalidate_partition(struct gendisk *, int);
1370unsigned long invalidate_mapping_pages(struct address_space *mapping,
1371 pgoff_t start, pgoff_t end);
1372unsigned long invalidate_inode_pages(struct address_space *mapping);
1373static inline void invalidate_remote_inode(struct inode *inode)
1374{
1375 if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
1376 S_ISLNK(inode->i_mode))
1377 invalidate_inode_pages(inode->i_mapping);
1378}
1379extern int invalidate_inode_pages2(struct address_space *mapping);
1380extern int invalidate_inode_pages2_range(struct address_space *mapping,
1381 pgoff_t start, pgoff_t end);
1382extern int write_inode_now(struct inode *, int);
1383extern int filemap_fdatawrite(struct address_space *);
1384extern int filemap_flush(struct address_space *);
1385extern int filemap_fdatawait(struct address_space *);
1386extern int filemap_write_and_wait(struct address_space *mapping);
1387extern int filemap_write_and_wait_range(struct address_space *mapping,
1388 loff_t lstart, loff_t lend);
1389extern void sync_supers(void);
1390extern void sync_filesystems(int wait);
1391extern void emergency_sync(void);
1392extern void emergency_remount(void);
1393extern int do_remount_sb(struct super_block *sb, int flags,
1394 void *data, int force);
1395extern sector_t bmap(struct inode *, sector_t);
1396extern int setattr_mask(unsigned int);
1397extern int notify_change(struct dentry *, struct iattr *);
1398extern int permission(struct inode *, int, struct nameidata *);
1399extern int generic_permission(struct inode *, int,
1400 int (*check_acl)(struct inode *, int));
1401
1402extern int get_write_access(struct inode *);
1403extern int deny_write_access(struct file *);
1404static inline void put_write_access(struct inode * inode)
1405{
1406 atomic_dec(&inode->i_writecount);
1407}
1408static inline void allow_write_access(struct file *file)
1409{
1410 if (file)
1411 atomic_inc(&file->f_dentry->d_inode->i_writecount);
1412}
1413extern int do_pipe(int *);
1414
1415extern int open_namei(const char *, int, int, struct nameidata *);
1416extern int may_open(struct nameidata *, int, int);
1417
1418extern int kernel_read(struct file *, unsigned long, char *, unsigned long);
1419extern struct file * open_exec(const char *);
1420
1421/* fs/dcache.c -- generic fs support functions */
1422extern int is_subdir(struct dentry *, struct dentry *);
1423extern ino_t find_inode_number(struct dentry *, struct qstr *);
1424
1425#include <linux/err.h>
1426
1427/* needed for stackable file system support */
1428extern loff_t default_llseek(struct file *file, loff_t offset, int origin);
1429
1430extern loff_t vfs_llseek(struct file *file, loff_t offset, int origin);
1431
1432extern void inode_init_once(struct inode *);
1433extern void iput(struct inode *);
1434extern struct inode * igrab(struct inode *);
1435extern ino_t iunique(struct super_block *, ino_t);
1436extern int inode_needs_sync(struct inode *inode);
1437extern void generic_delete_inode(struct inode *inode);
cb2c0233 1438extern void generic_drop_inode(struct inode *inode);
1da177e4
LT
1439
1440extern struct inode *ilookup5(struct super_block *sb, unsigned long hashval,
1441 int (*test)(struct inode *, void *), void *data);
1442extern struct inode *ilookup(struct super_block *sb, unsigned long ino);
1443
1444extern struct inode * iget5_locked(struct super_block *, unsigned long, int (*test)(struct inode *, void *), int (*set)(struct inode *, void *), void *);
1445extern struct inode * iget_locked(struct super_block *, unsigned long);
1446extern void unlock_new_inode(struct inode *);
1447
1448static inline struct inode *iget(struct super_block *sb, unsigned long ino)
1449{
1450 struct inode *inode = iget_locked(sb, ino);
1451
1452 if (inode && (inode->i_state & I_NEW)) {
1453 sb->s_op->read_inode(inode);
1454 unlock_new_inode(inode);
1455 }
1456
1457 return inode;
1458}
1459
1460extern void __iget(struct inode * inode);
1461extern void clear_inode(struct inode *);
1462extern void destroy_inode(struct inode *);
1463extern struct inode *new_inode(struct super_block *);
1464extern int remove_suid(struct dentry *);
1465extern void remove_dquot_ref(struct super_block *, int, struct list_head *);
1466extern struct semaphore iprune_sem;
1467
1468extern void __insert_inode_hash(struct inode *, unsigned long hashval);
1469extern void remove_inode_hash(struct inode *);
1470static inline void insert_inode_hash(struct inode *inode) {
1471 __insert_inode_hash(inode, inode->i_ino);
1472}
1473
1474extern struct file * get_empty_filp(void);
1475extern void file_move(struct file *f, struct list_head *list);
1476extern void file_kill(struct file *f);
1477struct bio;
1478extern void submit_bio(int, struct bio *);
1479extern int bdev_read_only(struct block_device *);
1480extern int set_blocksize(struct block_device *, int);
1481extern int sb_set_blocksize(struct super_block *, int);
1482extern int sb_min_blocksize(struct super_block *, int);
1483
1484extern int generic_file_mmap(struct file *, struct vm_area_struct *);
1485extern int generic_file_readonly_mmap(struct file *, struct vm_area_struct *);
1486extern int file_read_actor(read_descriptor_t * desc, struct page *page, unsigned long offset, unsigned long size);
1487extern int file_send_actor(read_descriptor_t * desc, struct page *page, unsigned long offset, unsigned long size);
1488extern ssize_t generic_file_read(struct file *, char __user *, size_t, loff_t *);
1489int generic_write_checks(struct file *file, loff_t *pos, size_t *count, int isblk);
1490extern ssize_t generic_file_write(struct file *, const char __user *, size_t, loff_t *);
1491extern ssize_t generic_file_aio_read(struct kiocb *, char __user *, size_t, loff_t);
1492extern ssize_t __generic_file_aio_read(struct kiocb *, const struct iovec *, unsigned long, loff_t *);
1493extern ssize_t generic_file_aio_write(struct kiocb *, const char __user *, size_t, loff_t);
1494extern ssize_t generic_file_aio_write_nolock(struct kiocb *, const struct iovec *,
1495 unsigned long, loff_t *);
1496extern ssize_t generic_file_direct_write(struct kiocb *, const struct iovec *,
1497 unsigned long *, loff_t, loff_t *, size_t, size_t);
1498extern ssize_t generic_file_buffered_write(struct kiocb *, const struct iovec *,
1499 unsigned long, loff_t, loff_t *, size_t, ssize_t);
1500extern ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos);
1501extern ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos);
1502ssize_t generic_file_write_nolock(struct file *file, const struct iovec *iov,
1503 unsigned long nr_segs, loff_t *ppos);
1504extern ssize_t generic_file_sendfile(struct file *, loff_t *, size_t, read_actor_t, void *);
1505extern void do_generic_mapping_read(struct address_space *mapping,
1506 struct file_ra_state *, struct file *,
1507 loff_t *, read_descriptor_t *, read_actor_t);
1508extern void
1509file_ra_state_init(struct file_ra_state *ra, struct address_space *mapping);
1510extern ssize_t generic_file_direct_IO(int rw, struct kiocb *iocb,
1511 const struct iovec *iov, loff_t offset, unsigned long nr_segs);
1512extern ssize_t generic_file_readv(struct file *filp, const struct iovec *iov,
1513 unsigned long nr_segs, loff_t *ppos);
1514ssize_t generic_file_writev(struct file *filp, const struct iovec *iov,
1515 unsigned long nr_segs, loff_t *ppos);
1516extern loff_t no_llseek(struct file *file, loff_t offset, int origin);
1517extern loff_t generic_file_llseek(struct file *file, loff_t offset, int origin);
1518extern loff_t remote_llseek(struct file *file, loff_t offset, int origin);
1519extern int generic_file_open(struct inode * inode, struct file * filp);
1520extern int nonseekable_open(struct inode * inode, struct file * filp);
1521
ceffc078 1522#ifdef CONFIG_FS_XIP
eb6fe0c3
CO
1523extern ssize_t xip_file_read(struct file *filp, char __user *buf, size_t len,
1524 loff_t *ppos);
ceffc078
CO
1525extern ssize_t xip_file_sendfile(struct file *in_file, loff_t *ppos,
1526 size_t count, read_actor_t actor,
1527 void *target);
1528extern int xip_file_mmap(struct file * file, struct vm_area_struct * vma);
eb6fe0c3
CO
1529extern ssize_t xip_file_write(struct file *filp, const char __user *buf,
1530 size_t len, loff_t *ppos);
ceffc078 1531extern int xip_truncate_page(struct address_space *mapping, loff_t from);
6d79125b
CO
1532#else
1533static inline int xip_truncate_page(struct address_space *mapping, loff_t from)
1534{
1535 return 0;
1536}
ceffc078
CO
1537#endif
1538
1da177e4
LT
1539static inline void do_generic_file_read(struct file * filp, loff_t *ppos,
1540 read_descriptor_t * desc,
1541 read_actor_t actor)
1542{
1543 do_generic_mapping_read(filp->f_mapping,
1544 &filp->f_ra,
1545 filp,
1546 ppos,
1547 desc,
1548 actor);
1549}
1550
1551ssize_t __blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode,
1552 struct block_device *bdev, const struct iovec *iov, loff_t offset,
1553 unsigned long nr_segs, get_blocks_t get_blocks, dio_iodone_t end_io,
1554 int lock_type);
1555
1556enum {
1557 DIO_LOCKING = 1, /* need locking between buffered and direct access */
1558 DIO_NO_LOCKING, /* bdev; no locking at all between buffered/direct */
1559 DIO_OWN_LOCKING, /* filesystem locks buffered and direct internally */
1560};
1561
1562static inline ssize_t blockdev_direct_IO(int rw, struct kiocb *iocb,
1563 struct inode *inode, struct block_device *bdev, const struct iovec *iov,
1564 loff_t offset, unsigned long nr_segs, get_blocks_t get_blocks,
1565 dio_iodone_t end_io)
1566{
1567 return __blockdev_direct_IO(rw, iocb, inode, bdev, iov, offset,
1568 nr_segs, get_blocks, end_io, DIO_LOCKING);
1569}
1570
1571static inline ssize_t blockdev_direct_IO_no_locking(int rw, struct kiocb *iocb,
1572 struct inode *inode, struct block_device *bdev, const struct iovec *iov,
1573 loff_t offset, unsigned long nr_segs, get_blocks_t get_blocks,
1574 dio_iodone_t end_io)
1575{
1576 return __blockdev_direct_IO(rw, iocb, inode, bdev, iov, offset,
1577 nr_segs, get_blocks, end_io, DIO_NO_LOCKING);
1578}
1579
1580static inline ssize_t blockdev_direct_IO_own_locking(int rw, struct kiocb *iocb,
1581 struct inode *inode, struct block_device *bdev, const struct iovec *iov,
1582 loff_t offset, unsigned long nr_segs, get_blocks_t get_blocks,
1583 dio_iodone_t end_io)
1584{
1585 return __blockdev_direct_IO(rw, iocb, inode, bdev, iov, offset,
1586 nr_segs, get_blocks, end_io, DIO_OWN_LOCKING);
1587}
1588
1589extern struct file_operations generic_ro_fops;
1590
1591#define special_file(m) (S_ISCHR(m)||S_ISBLK(m)||S_ISFIFO(m)||S_ISSOCK(m))
1592
1593extern int vfs_readlink(struct dentry *, char __user *, int, const char *);
1594extern int vfs_follow_link(struct nameidata *, const char *);
1595extern int page_readlink(struct dentry *, char __user *, int);
1596extern int page_follow_link_light(struct dentry *, struct nameidata *);
1597extern void page_put_link(struct dentry *, struct nameidata *);
1598extern int page_symlink(struct inode *inode, const char *symname, int len);
1599extern struct inode_operations page_symlink_inode_operations;
1600extern int generic_readlink(struct dentry *, char __user *, int);
1601extern void generic_fillattr(struct inode *, struct kstat *);
1602extern int vfs_getattr(struct vfsmount *, struct dentry *, struct kstat *);
1603void inode_add_bytes(struct inode *inode, loff_t bytes);
1604void inode_sub_bytes(struct inode *inode, loff_t bytes);
1605loff_t inode_get_bytes(struct inode *inode);
1606void inode_set_bytes(struct inode *inode, loff_t bytes);
1607
1608extern int vfs_readdir(struct file *, filldir_t, void *);
1609
1610extern int vfs_stat(char __user *, struct kstat *);
1611extern int vfs_lstat(char __user *, struct kstat *);
1612extern int vfs_fstat(unsigned int, struct kstat *);
1613
1614extern int vfs_ioctl(struct file *, unsigned int, unsigned int, unsigned long);
1615
1616extern struct file_system_type *get_fs_type(const char *name);
1617extern struct super_block *get_super(struct block_device *);
1618extern struct super_block *user_get_super(dev_t);
1619extern void drop_super(struct super_block *sb);
1620
1621extern int dcache_dir_open(struct inode *, struct file *);
1622extern int dcache_dir_close(struct inode *, struct file *);
1623extern loff_t dcache_dir_lseek(struct file *, loff_t, int);
1624extern int dcache_readdir(struct file *, void *, filldir_t);
1625extern int simple_getattr(struct vfsmount *, struct dentry *, struct kstat *);
1626extern int simple_statfs(struct super_block *, struct kstatfs *);
1627extern int simple_link(struct dentry *, struct inode *, struct dentry *);
1628extern int simple_unlink(struct inode *, struct dentry *);
1629extern int simple_rmdir(struct inode *, struct dentry *);
1630extern int simple_rename(struct inode *, struct dentry *, struct inode *, struct dentry *);
1631extern int simple_sync_file(struct file *, struct dentry *, int);
1632extern int simple_empty(struct dentry *);
1633extern int simple_readpage(struct file *file, struct page *page);
1634extern int simple_prepare_write(struct file *file, struct page *page,
1635 unsigned offset, unsigned to);
1636extern int simple_commit_write(struct file *file, struct page *page,
1637 unsigned offset, unsigned to);
1638
1639extern struct dentry *simple_lookup(struct inode *, struct dentry *, struct nameidata *);
1640extern ssize_t generic_read_dir(struct file *, char __user *, size_t, loff_t *);
1641extern struct file_operations simple_dir_operations;
1642extern struct inode_operations simple_dir_inode_operations;
1643struct tree_descr { char *name; struct file_operations *ops; int mode; };
1644struct dentry *d_alloc_name(struct dentry *, const char *);
1645extern int simple_fill_super(struct super_block *, int, struct tree_descr *);
1646extern int simple_pin_fs(char *name, struct vfsmount **mount, int *count);
1647extern void simple_release_fs(struct vfsmount **mount, int *count);
1648
1649extern ssize_t simple_read_from_buffer(void __user *, size_t, loff_t *, const void *, size_t);
1650
1651extern int inode_change_ok(struct inode *, struct iattr *);
1652extern int __must_check inode_setattr(struct inode *, struct iattr *);
1653
1654extern void inode_update_time(struct inode *inode, int ctime_too);
1655
1656static inline ino_t parent_ino(struct dentry *dentry)
1657{
1658 ino_t res;
1659
1660 spin_lock(&dentry->d_lock);
1661 res = dentry->d_parent->d_inode->i_ino;
1662 spin_unlock(&dentry->d_lock);
1663 return res;
1664}
1665
1666/* kernel/fork.c */
1667extern int unshare_files(void);
1668
1669/* Transaction based IO helpers */
1670
1671/*
1672 * An argresp is stored in an allocated page and holds the
1673 * size of the argument or response, along with its content
1674 */
1675struct simple_transaction_argresp {
1676 ssize_t size;
1677 char data[0];
1678};
1679
1680#define SIMPLE_TRANSACTION_LIMIT (PAGE_SIZE - sizeof(struct simple_transaction_argresp))
1681
1682char *simple_transaction_get(struct file *file, const char __user *buf,
1683 size_t size);
1684ssize_t simple_transaction_read(struct file *file, char __user *buf,
1685 size_t size, loff_t *pos);
1686int simple_transaction_release(struct inode *inode, struct file *file);
1687
1688static inline void simple_transaction_set(struct file *file, size_t n)
1689{
1690 struct simple_transaction_argresp *ar = file->private_data;
1691
1692 BUG_ON(n > SIMPLE_TRANSACTION_LIMIT);
1693
1694 /*
1695 * The barrier ensures that ar->size will really remain zero until
1696 * ar->data is ready for reading.
1697 */
1698 smp_mb();
1699 ar->size = n;
1700}
1701
acaefc25
AB
1702/*
1703 * simple attribute files
1704 *
1705 * These attributes behave similar to those in sysfs:
1706 *
1707 * Writing to an attribute immediately sets a value, an open file can be
1708 * written to multiple times.
1709 *
1710 * Reading from an attribute creates a buffer from the value that might get
1711 * read with multiple read calls. When the attribute has been read
1712 * completely, no further read calls are possible until the file is opened
1713 * again.
1714 *
1715 * All attributes contain a text representation of a numeric value
1716 * that are accessed with the get() and set() functions.
1717 */
1718#define DEFINE_SIMPLE_ATTRIBUTE(__fops, __get, __set, __fmt) \
1719static int __fops ## _open(struct inode *inode, struct file *file) \
1720{ \
1721 __simple_attr_check_format(__fmt, 0ull); \
1722 return simple_attr_open(inode, file, __get, __set, __fmt); \
1723} \
1724static struct file_operations __fops = { \
1725 .owner = THIS_MODULE, \
1726 .open = __fops ## _open, \
1727 .release = simple_attr_close, \
1728 .read = simple_attr_read, \
1729 .write = simple_attr_write, \
1730};
1731
1732static inline void __attribute__((format(printf, 1, 2)))
1733__simple_attr_check_format(const char *fmt, ...)
1734{
1735 /* don't do anything, just let the compiler check the arguments; */
1736}
1737
1738int simple_attr_open(struct inode *inode, struct file *file,
1739 u64 (*get)(void *), void (*set)(void *, u64),
1740 const char *fmt);
1741int simple_attr_close(struct inode *inode, struct file *file);
1742ssize_t simple_attr_read(struct file *file, char __user *buf,
1743 size_t len, loff_t *ppos);
1744ssize_t simple_attr_write(struct file *file, const char __user *buf,
1745 size_t len, loff_t *ppos);
1746
1747
1da177e4
LT
1748#ifdef CONFIG_SECURITY
1749static inline char *alloc_secdata(void)
1750{
1751 return (char *)get_zeroed_page(GFP_KERNEL);
1752}
1753
1754static inline void free_secdata(void *secdata)
1755{
1756 free_page((unsigned long)secdata);
1757}
1758#else
1759static inline char *alloc_secdata(void)
1760{
1761 return (char *)1;
1762}
1763
1764static inline void free_secdata(void *secdata)
1765{ }
1766#endif /* CONFIG_SECURITY */
1767
1768#endif /* __KERNEL__ */
1769#endif /* _LINUX_FS_H */