~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/include/linux/fs.h

Version: ~ [ linux-5.6 ] ~ [ linux-5.5.13 ] ~ [ linux-5.4.28 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.113 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.174 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.217 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.217 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.82 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 #ifndef _LINUX_FS_H
  2 #define _LINUX_FS_H
  3 
  4 
  5 #include <linux/linkage.h>
  6 #include <linux/wait.h>
  7 #include <linux/kdev_t.h>
  8 #include <linux/dcache.h>
  9 #include <linux/path.h>
 10 #include <linux/stat.h>
 11 #include <linux/cache.h>
 12 #include <linux/list.h>
 13 #include <linux/list_lru.h>
 14 #include <linux/llist.h>
 15 #include <linux/radix-tree.h>
 16 #include <linux/rbtree.h>
 17 #include <linux/init.h>
 18 #include <linux/pid.h>
 19 #include <linux/bug.h>
 20 #include <linux/mutex.h>
 21 #include <linux/capability.h>
 22 #include <linux/semaphore.h>
 23 #include <linux/fiemap.h>
 24 #include <linux/rculist_bl.h>
 25 #include <linux/atomic.h>
 26 #include <linux/shrinker.h>
 27 #include <linux/migrate_mode.h>
 28 #include <linux/uidgid.h>
 29 #include <linux/lockdep.h>
 30 #include <linux/percpu-rwsem.h>
 31 #include <linux/blk_types.h>
 32 
 33 #include <asm/byteorder.h>
 34 #include <uapi/linux/fs.h>
 35 
 36 struct export_operations;
 37 struct hd_geometry;
 38 struct iovec;
 39 struct nameidata;
 40 struct kiocb;
 41 struct kobject;
 42 struct pipe_inode_info;
 43 struct poll_table_struct;
 44 struct kstatfs;
 45 struct vm_area_struct;
 46 struct vfsmount;
 47 struct cred;
 48 struct swap_info_struct;
 49 struct seq_file;
 50 struct workqueue_struct;
 51 
 52 extern void __init inode_init(void);
 53 extern void __init inode_init_early(void);
 54 extern void __init files_init(unsigned long);
 55 
 56 extern struct files_stat_struct files_stat;
 57 extern unsigned long get_max_files(void);
 58 extern int sysctl_nr_open;
 59 extern struct inodes_stat_t inodes_stat;
 60 extern int leases_enable, lease_break_time;
 61 extern int sysctl_protected_symlinks;
 62 extern int sysctl_protected_hardlinks;
 63 
 64 struct buffer_head;
 65 typedef int (get_block_t)(struct inode *inode, sector_t iblock,
 66                         struct buffer_head *bh_result, int create);
 67 typedef void (dio_iodone_t)(struct kiocb *iocb, loff_t offset,
 68                         ssize_t bytes, void *private);
 69 
 70 #define MAY_EXEC                0x00000001
 71 #define MAY_WRITE               0x00000002
 72 #define MAY_READ                0x00000004
 73 #define MAY_APPEND              0x00000008
 74 #define MAY_ACCESS              0x00000010
 75 #define MAY_OPEN                0x00000020
 76 #define MAY_CHDIR               0x00000040
 77 /* called from RCU mode, don't block */
 78 #define MAY_NOT_BLOCK           0x00000080
 79 
 80 /*
 81  * flags in file.f_mode.  Note that FMODE_READ and FMODE_WRITE must correspond
 82  * to O_WRONLY and O_RDWR via the strange trick in __dentry_open()
 83  */
 84 
 85 /* file is open for reading */
 86 #define FMODE_READ              ((__force fmode_t)0x1)
 87 /* file is open for writing */
 88 #define FMODE_WRITE             ((__force fmode_t)0x2)
 89 /* file is seekable */
 90 #define FMODE_LSEEK             ((__force fmode_t)0x4)
 91 /* file can be accessed using pread */
 92 #define FMODE_PREAD             ((__force fmode_t)0x8)
 93 /* file can be accessed using pwrite */
 94 #define FMODE_PWRITE            ((__force fmode_t)0x10)
 95 /* File is opened for execution with sys_execve / sys_uselib */
 96 #define FMODE_EXEC              ((__force fmode_t)0x20)
 97 /* File is opened with O_NDELAY (only set for block devices) */
 98 #define FMODE_NDELAY            ((__force fmode_t)0x40)
 99 /* File is opened with O_EXCL (only set for block devices) */
100 #define FMODE_EXCL              ((__force fmode_t)0x80)
101 /* File is opened using open(.., 3, ..) and is writeable only for ioctls
102    (specialy hack for floppy.c) */
103 #define FMODE_WRITE_IOCTL       ((__force fmode_t)0x100)
104 /* 32bit hashes as llseek() offset (for directories) */
105 #define FMODE_32BITHASH         ((__force fmode_t)0x200)
106 /* 64bit hashes as llseek() offset (for directories) */
107 #define FMODE_64BITHASH         ((__force fmode_t)0x400)
108 
109 /*
110  * Don't update ctime and mtime.
111  *
112  * Currently a special hack for the XFS open_by_handle ioctl, but we'll
113  * hopefully graduate it to a proper O_CMTIME flag supported by open(2) soon.
114  */
115 #define FMODE_NOCMTIME          ((__force fmode_t)0x800)
116 
117 /* Expect random access pattern */
118 #define FMODE_RANDOM            ((__force fmode_t)0x1000)
119 
120 /* File is huge (eg. /dev/kmem): treat loff_t as unsigned */
121 #define FMODE_UNSIGNED_OFFSET   ((__force fmode_t)0x2000)
122 
123 /* File is opened with O_PATH; almost nothing can be done with it */
124 #define FMODE_PATH              ((__force fmode_t)0x4000)
125 
126 /* File was opened by fanotify and shouldn't generate fanotify events */
127 #define FMODE_NONOTIFY          ((__force fmode_t)0x1000000)
128 
129 /*
130  * Flag for rw_copy_check_uvector and compat_rw_copy_check_uvector
131  * that indicates that they should check the contents of the iovec are
132  * valid, but not check the memory that the iovec elements
133  * points too.
134  */
135 #define CHECK_IOVEC_ONLY -1
136 
137 /*
138  * The below are the various read and write types that we support. Some of
139  * them include behavioral modifiers that send information down to the
140  * block layer and IO scheduler. Terminology:
141  *
142  *      The block layer uses device plugging to defer IO a little bit, in
143  *      the hope that we will see more IO very shortly. This increases
144  *      coalescing of adjacent IO and thus reduces the number of IOs we
145  *      have to send to the device. It also allows for better queuing,
146  *      if the IO isn't mergeable. If the caller is going to be waiting
147  *      for the IO, then he must ensure that the device is unplugged so
148  *      that the IO is dispatched to the driver.
149  *
150  *      All IO is handled async in Linux. This is fine for background
151  *      writes, but for reads or writes that someone waits for completion
152  *      on, we want to notify the block layer and IO scheduler so that they
153  *      know about it. That allows them to make better scheduling
154  *      decisions. So when the below references 'sync' and 'async', it
155  *      is referencing this priority hint.
156  *
157  * With that in mind, the available types are:
158  *
159  * READ                 A normal read operation. Device will be plugged.
160  * READ_SYNC            A synchronous read. Device is not plugged, caller can
161  *                      immediately wait on this read without caring about
162  *                      unplugging.
163  * READA                Used for read-ahead operations. Lower priority, and the
164  *                      block layer could (in theory) choose to ignore this
165  *                      request if it runs into resource problems.
166  * WRITE                A normal async write. Device will be plugged.
167  * WRITE_SYNC           Synchronous write. Identical to WRITE, but passes down
168  *                      the hint that someone will be waiting on this IO
169  *                      shortly. The write equivalent of READ_SYNC.
170  * WRITE_ODIRECT        Special case write for O_DIRECT only.
171  * WRITE_FLUSH          Like WRITE_SYNC but with preceding cache flush.
172  * WRITE_FUA            Like WRITE_SYNC but data is guaranteed to be on
173  *                      non-volatile media on completion.
174  * WRITE_FLUSH_FUA      Combination of WRITE_FLUSH and FUA. The IO is preceded
175  *                      by a cache flush and data is guaranteed to be on
176  *                      non-volatile media on completion.
177  *
178  */
179 #define RW_MASK                 REQ_WRITE
180 #define RWA_MASK                REQ_RAHEAD
181 
182 #define READ                    0
183 #define WRITE                   RW_MASK
184 #define READA                   RWA_MASK
185 #define KERNEL_READ             (READ|REQ_KERNEL)
186 #define KERNEL_WRITE            (WRITE|REQ_KERNEL)
187 
188 #define READ_SYNC               (READ | REQ_SYNC)
189 #define WRITE_SYNC              (WRITE | REQ_SYNC | REQ_NOIDLE)
190 #define WRITE_ODIRECT           (WRITE | REQ_SYNC)
191 #define WRITE_FLUSH             (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_FLUSH)
192 #define WRITE_FUA               (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_FUA)
193 #define WRITE_FLUSH_FUA         (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_FLUSH | REQ_FUA)
194 
195 /*
196  * Attribute flags.  These should be or-ed together to figure out what
197  * has been changed!
198  */
199 #define ATTR_MODE       (1 << 0)
200 #define ATTR_UID        (1 << 1)
201 #define ATTR_GID        (1 << 2)
202 #define ATTR_SIZE       (1 << 3)
203 #define ATTR_ATIME      (1 << 4)
204 #define ATTR_MTIME      (1 << 5)
205 #define ATTR_CTIME      (1 << 6)
206 #define ATTR_ATIME_SET  (1 << 7)
207 #define ATTR_MTIME_SET  (1 << 8)
208 #define ATTR_FORCE      (1 << 9) /* Not a change, but a change it */
209 #define ATTR_ATTR_FLAG  (1 << 10)
210 #define ATTR_KILL_SUID  (1 << 11)
211 #define ATTR_KILL_SGID  (1 << 12)
212 #define ATTR_FILE       (1 << 13)
213 #define ATTR_KILL_PRIV  (1 << 14)
214 #define ATTR_OPEN       (1 << 15) /* Truncating from open(O_TRUNC) */
215 #define ATTR_TIMES_SET  (1 << 16)
216 
217 /*
218  * This is the Inode Attributes structure, used for notify_change().  It
219  * uses the above definitions as flags, to know which values have changed.
220  * Also, in this manner, a Filesystem can look at only the values it cares
221  * about.  Basically, these are the attributes that the VFS layer can
222  * request to change from the FS layer.
223  *
224  * Derek Atkins <warlord@MIT.EDU> 94-10-20
225  */
226 struct iattr {
227         unsigned int    ia_valid;
228         umode_t         ia_mode;
229         kuid_t          ia_uid;
230         kgid_t          ia_gid;
231         loff_t          ia_size;
232         struct timespec ia_atime;
233         struct timespec ia_mtime;
234         struct timespec ia_ctime;
235 
236         /*
237          * Not an attribute, but an auxiliary info for filesystems wanting to
238          * implement an ftruncate() like method.  NOTE: filesystem should
239          * check for (ia_valid & ATTR_FILE), and not for (ia_file != NULL).
240          */
241         struct file     *ia_file;
242 };
243 
244 /*
245  * Includes for diskquotas.
246  */
247 #include <linux/quota.h>
248 
249 /** 
250  * enum positive_aop_returns - aop return codes with specific semantics
251  *
252  * @AOP_WRITEPAGE_ACTIVATE: Informs the caller that page writeback has
253  *                          completed, that the page is still locked, and
254  *                          should be considered active.  The VM uses this hint
255  *                          to return the page to the active list -- it won't
256  *                          be a candidate for writeback again in the near
257  *                          future.  Other callers must be careful to unlock
258  *                          the page if they get this return.  Returned by
259  *                          writepage(); 
260  *
261  * @AOP_TRUNCATED_PAGE: The AOP method that was handed a locked page has
262  *                      unlocked it and the page might have been truncated.
263  *                      The caller should back up to acquiring a new page and
264  *                      trying again.  The aop will be taking reasonable
265  *                      precautions not to livelock.  If the caller held a page
266  *                      reference, it should drop it before retrying.  Returned
267  *                      by readpage().
268  *
269  * address_space_operation functions return these large constants to indicate
270  * special semantics to the caller.  These are much larger than the bytes in a
271  * page to allow for functions that return the number of bytes operated on in a
272  * given page.
273  */
274 
275 enum positive_aop_returns {
276         AOP_WRITEPAGE_ACTIVATE  = 0x80000,
277         AOP_TRUNCATED_PAGE      = 0x80001,
278 };
279 
280 #define AOP_FLAG_UNINTERRUPTIBLE        0x0001 /* will not do a short write */
281 #define AOP_FLAG_CONT_EXPAND            0x0002 /* called from cont_expand */
282 #define AOP_FLAG_NOFS                   0x0004 /* used by filesystem to direct
283                                                 * helper code (eg buffer layer)
284                                                 * to clear GFP_FS from alloc */
285 
286 /*
287  * oh the beauties of C type declarations.
288  */
289 struct page;
290 struct address_space;
291 struct writeback_control;
292 
293 struct iov_iter {
294         const struct iovec *iov;
295         unsigned long nr_segs;
296         size_t iov_offset;
297         size_t count;
298 };
299 
300 size_t iov_iter_copy_from_user_atomic(struct page *page,
301                 struct iov_iter *i, unsigned long offset, size_t bytes);
302 size_t iov_iter_copy_from_user(struct page *page,
303                 struct iov_iter *i, unsigned long offset, size_t bytes);
304 void iov_iter_advance(struct iov_iter *i, size_t bytes);
305 int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes);
306 size_t iov_iter_single_seg_count(const struct iov_iter *i);
307 
308 static inline void iov_iter_init(struct iov_iter *i,
309                         const struct iovec *iov, unsigned long nr_segs,
310                         size_t count, size_t written)
311 {
312         i->iov = iov;
313         i->nr_segs = nr_segs;
314         i->iov_offset = 0;
315         i->count = count + written;
316 
317         iov_iter_advance(i, written);
318 }
319 
320 static inline size_t iov_iter_count(struct iov_iter *i)
321 {
322         return i->count;
323 }
324 
325 /*
326  * "descriptor" for what we're up to with a read.
327  * This allows us to use the same read code yet
328  * have multiple different users of the data that
329  * we read from a file.
330  *
331  * The simplest case just copies the data to user
332  * mode.
333  */
334 typedef struct {
335         size_t written;
336         size_t count;
337         union {
338                 char __user *buf;
339                 void *data;
340         } arg;
341         int error;
342 } read_descriptor_t;
343 
344 typedef int (*read_actor_t)(read_descriptor_t *, struct page *,
345                 unsigned long, unsigned long);
346 
347 struct address_space_operations {
348         int (*writepage)(struct page *page, struct writeback_control *wbc);
349         int (*readpage)(struct file *, struct page *);
350 
351         /* Write back some dirty pages from this mapping. */
352         int (*writepages)(struct address_space *, struct writeback_control *);
353 
354         /* Set a page dirty.  Return true if this dirtied it */
355         int (*set_page_dirty)(struct page *page);
356 
357         int (*readpages)(struct file *filp, struct address_space *mapping,
358                         struct list_head *pages, unsigned nr_pages);
359 
360         int (*write_begin)(struct file *, struct address_space *mapping,
361                                 loff_t pos, unsigned len, unsigned flags,
362                                 struct page **pagep, void **fsdata);
363         int (*write_end)(struct file *, struct address_space *mapping,
364                                 loff_t pos, unsigned len, unsigned copied,
365                                 struct page *page, void *fsdata);
366 
367         /* Unfortunately this kludge is needed for FIBMAP. Don't use it */
368         sector_t (*bmap)(struct address_space *, sector_t);
369         void (*invalidatepage) (struct page *, unsigned int, unsigned int);
370         int (*releasepage) (struct page *, gfp_t);
371         void (*freepage)(struct page *);
372         ssize_t (*direct_IO)(int, struct kiocb *, const struct iovec *iov,
373                         loff_t offset, unsigned long nr_segs);
374         int (*get_xip_mem)(struct address_space *, pgoff_t, int,
375                                                 void **, unsigned long *);
376         /*
377          * migrate the contents of a page to the specified target. If
378          * migrate_mode is MIGRATE_ASYNC, it must not block.
379          */
380         int (*migratepage) (struct address_space *,
381                         struct page *, struct page *, enum migrate_mode);
382         int (*launder_page) (struct page *);
383         int (*is_partially_uptodate) (struct page *, read_descriptor_t *,
384                                         unsigned long);
385         void (*is_dirty_writeback) (struct page *, bool *, bool *);
386         int (*error_remove_page)(struct address_space *, struct page *);
387 
388         /* swapfile support */
389         int (*swap_activate)(struct swap_info_struct *sis, struct file *file,
390                                 sector_t *span);
391         void (*swap_deactivate)(struct file *file);
392 };
393 
394 extern const struct address_space_operations empty_aops;
395 
396 /*
397  * pagecache_write_begin/pagecache_write_end must be used by general code
398  * to write into the pagecache.
399  */
400 int pagecache_write_begin(struct file *, struct address_space *mapping,
401                                 loff_t pos, unsigned len, unsigned flags,
402                                 struct page **pagep, void **fsdata);
403 
404 int pagecache_write_end(struct file *, struct address_space *mapping,
405                                 loff_t pos, unsigned len, unsigned copied,
406                                 struct page *page, void *fsdata);
407 
408 struct backing_dev_info;
409 struct address_space {
410         struct inode            *host;          /* owner: inode, block_device */
411         struct radix_tree_root  page_tree;      /* radix tree of all pages */
412         spinlock_t              tree_lock;      /* and lock protecting it */
413         unsigned int            i_mmap_writable;/* count VM_SHARED mappings */
414         struct rb_root          i_mmap;         /* tree of private and shared mappings */
415         struct list_head        i_mmap_nonlinear;/*list VM_NONLINEAR mappings */
416         struct mutex            i_mmap_mutex;   /* protect tree, count, list */
417         /* Protected by tree_lock together with the radix tree */
418         unsigned long           nrpages;        /* number of total pages */
419         pgoff_t                 writeback_index;/* writeback starts here */
420         const struct address_space_operations *a_ops;   /* methods */
421         unsigned long           flags;          /* error bits/gfp mask */
422         struct backing_dev_info *backing_dev_info; /* device readahead, etc */
423         spinlock_t              private_lock;   /* for use by the address_space */
424         struct list_head        private_list;   /* ditto */
425         void                    *private_data;  /* ditto */
426 } __attribute__((aligned(sizeof(long))));
427         /*
428          * On most architectures that alignment is already the case; but
429          * must be enforced here for CRIS, to let the least significant bit
430          * of struct page's "mapping" pointer be used for PAGE_MAPPING_ANON.
431          */
432 struct request_queue;
433 
434 struct block_device {
435         dev_t                   bd_dev;  /* not a kdev_t - it's a search key */
436         int                     bd_openers;
437         struct inode *          bd_inode;       /* will die */
438         struct super_block *    bd_super;
439         struct mutex            bd_mutex;       /* open/close mutex */
440         struct list_head        bd_inodes;
441         void *                  bd_claiming;
442         void *                  bd_holder;
443         int                     bd_holders;
444         bool                    bd_write_holder;
445 #ifdef CONFIG_SYSFS
446         struct list_head        bd_holder_disks;
447 #endif
448         struct block_device *   bd_contains;
449         unsigned                bd_block_size;
450         struct hd_struct *      bd_part;
451         /* number of times partitions within this device have been opened. */
452         unsigned                bd_part_count;
453         int                     bd_invalidated;
454         struct gendisk *        bd_disk;
455         struct request_queue *  bd_queue;
456         struct list_head        bd_list;
457         /*
458          * Private data.  You must have bd_claim'ed the block_device
459          * to use this.  NOTE:  bd_claim allows an owner to claim
460          * the same device multiple times, the owner must take special
461          * care to not mess up bd_private for that case.
462          */
463         unsigned long           bd_private;
464 
465         /* The counter of freeze processes */
466         int                     bd_fsfreeze_count;
467         /* Mutex for freeze */
468         struct mutex            bd_fsfreeze_mutex;
469 };
470 
471 /*
472  * Radix-tree tags, for tagging dirty and writeback pages within the pagecache
473  * radix trees
474  */
475 #define PAGECACHE_TAG_DIRTY     0
476 #define PAGECACHE_TAG_WRITEBACK 1
477 #define PAGECACHE_TAG_TOWRITE   2
478 
479 int mapping_tagged(struct address_space *mapping, int tag);
480 
481 /*
482  * Might pages of this file be mapped into userspace?
483  */
484 static inline int mapping_mapped(struct address_space *mapping)
485 {
486         return  !RB_EMPTY_ROOT(&mapping->i_mmap) ||
487                 !list_empty(&mapping->i_mmap_nonlinear);
488 }
489 
490 /*
491  * Might pages of this file have been modified in userspace?
492  * Note that i_mmap_writable counts all VM_SHARED vmas: do_mmap_pgoff
493  * marks vma as VM_SHARED if it is shared, and the file was opened for
494  * writing i.e. vma may be mprotected writable even if now readonly.
495  */
496 static inline int mapping_writably_mapped(struct address_space *mapping)
497 {
498         return mapping->i_mmap_writable != 0;
499 }
500 
501 /*
502  * Use sequence counter to get consistent i_size on 32-bit processors.
503  */
504 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
505 #include <linux/seqlock.h>
506 #define __NEED_I_SIZE_ORDERED
507 #define i_size_ordered_init(inode) seqcount_init(&inode->i_size_seqcount)
508 #else
509 #define i_size_ordered_init(inode) do { } while (0)
510 #endif
511 
512 struct posix_acl;
513 #define ACL_NOT_CACHED ((void *)(-1))
514 
515 #define IOP_FASTPERM    0x0001
516 #define IOP_LOOKUP      0x0002
517 #define IOP_NOFOLLOW    0x0004
518 
519 /*
520  * Keep mostly read-only and often accessed (especially for
521  * the RCU path lookup and 'stat' data) fields at the beginning
522  * of the 'struct inode'
523  */
524 struct inode {
525         umode_t                 i_mode;
526         unsigned short          i_opflags;
527         kuid_t                  i_uid;
528         kgid_t                  i_gid;
529         unsigned int            i_flags;
530 
531 #ifdef CONFIG_FS_POSIX_ACL
532         struct posix_acl        *i_acl;
533         struct posix_acl        *i_default_acl;
534 #endif
535 
536         const struct inode_operations   *i_op;
537         struct super_block      *i_sb;
538         struct address_space    *i_mapping;
539 
540 #ifdef CONFIG_SECURITY
541         void                    *i_security;
542 #endif
543 
544         /* Stat data, not accessed from path walking */
545         unsigned long           i_ino;
546         /*
547          * Filesystems may only read i_nlink directly.  They shall use the
548          * following functions for modification:
549          *
550          *    (set|clear|inc|drop)_nlink
551          *    inode_(inc|dec)_link_count
552          */
553         union {
554                 const unsigned int i_nlink;
555                 unsigned int __i_nlink;
556         };
557         dev_t                   i_rdev;
558         loff_t                  i_size;
559         struct timespec         i_atime;
560         struct timespec         i_mtime;
561         struct timespec         i_ctime;
562         spinlock_t              i_lock; /* i_blocks, i_bytes, maybe i_size */
563         unsigned short          i_bytes;
564         unsigned int            i_blkbits;
565         blkcnt_t                i_blocks;
566 
567 #ifdef __NEED_I_SIZE_ORDERED
568         seqcount_t              i_size_seqcount;
569 #endif
570 
571         /* Misc */
572         unsigned long           i_state;
573         struct mutex            i_mutex;
574 
575         unsigned long           dirtied_when;   /* jiffies of first dirtying */
576 
577         struct hlist_node       i_hash;
578         struct list_head        i_wb_list;      /* backing dev IO list */
579         struct list_head        i_lru;          /* inode LRU list */
580         struct list_head        i_sb_list;
581         union {
582                 struct hlist_head       i_dentry;
583                 struct rcu_head         i_rcu;
584         };
585         u64                     i_version;
586         atomic_t                i_count;
587         atomic_t                i_dio_count;
588         atomic_t                i_writecount;
589         const struct file_operations    *i_fop; /* former ->i_op->default_file_ops */
590         struct file_lock        *i_flock;
591         struct address_space    i_data;
592 #ifdef CONFIG_QUOTA
593         struct dquot            *i_dquot[MAXQUOTAS];
594 #endif
595         struct list_head        i_devices;
596         union {
597                 struct pipe_inode_info  *i_pipe;
598                 struct block_device     *i_bdev;
599                 struct cdev             *i_cdev;
600         };
601 
602         __u32                   i_generation;
603 
604 #ifdef CONFIG_FSNOTIFY
605         __u32                   i_fsnotify_mask; /* all events this inode cares about */
606         struct hlist_head       i_fsnotify_marks;
607 #endif
608 
609 #ifdef CONFIG_IMA
610         atomic_t                i_readcount; /* struct files open RO */
611 #endif
612         void                    *i_private; /* fs or device private pointer */
613 };
614 
615 static inline int inode_unhashed(struct inode *inode)
616 {
617         return hlist_unhashed(&inode->i_hash);
618 }
619 
620 /*
621  * inode->i_mutex nesting subclasses for the lock validator:
622  *
623  * 0: the object of the current VFS operation
624  * 1: parent
625  * 2: child/target
626  * 3: xattr
627  * 4: second non-directory
628  * The last is for certain operations (such as rename) which lock two
629  * non-directories at once.
630  *
631  * The locking order between these classes is
632  * parent -> child -> normal -> xattr -> second non-directory
633  */
634 enum inode_i_mutex_lock_class
635 {
636         I_MUTEX_NORMAL,
637         I_MUTEX_PARENT,
638         I_MUTEX_CHILD,
639         I_MUTEX_XATTR,
640         I_MUTEX_NONDIR2
641 };
642 
643 void lock_two_nondirectories(struct inode *, struct inode*);
644 void unlock_two_nondirectories(struct inode *, struct inode*);
645 
646 /*
647  * NOTE: in a 32bit arch with a preemptable kernel and
648  * an UP compile the i_size_read/write must be atomic
649  * with respect to the local cpu (unlike with preempt disabled),
650  * but they don't need to be atomic with respect to other cpus like in
651  * true SMP (so they need either to either locally disable irq around
652  * the read or for example on x86 they can be still implemented as a
653  * cmpxchg8b without the need of the lock prefix). For SMP compiles
654  * and 64bit archs it makes no difference if preempt is enabled or not.
655  */
656 static inline loff_t i_size_read(const struct inode *inode)
657 {
658 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
659         loff_t i_size;
660         unsigned int seq;
661 
662         do {
663                 seq = read_seqcount_begin(&inode->i_size_seqcount);
664                 i_size = inode->i_size;
665         } while (read_seqcount_retry(&inode->i_size_seqcount, seq));
666         return i_size;
667 #elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT)
668         loff_t i_size;
669 
670         preempt_disable();
671         i_size = inode->i_size;
672         preempt_enable();
673         return i_size;
674 #else
675         return inode->i_size;
676 #endif
677 }
678 
679 /*
680  * NOTE: unlike i_size_read(), i_size_write() does need locking around it
681  * (normally i_mutex), otherwise on 32bit/SMP an update of i_size_seqcount
682  * can be lost, resulting in subsequent i_size_read() calls spinning forever.
683  */
684 static inline void i_size_write(struct inode *inode, loff_t i_size)
685 {
686 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
687         preempt_disable();
688         write_seqcount_begin(&inode->i_size_seqcount);
689         inode->i_size = i_size;
690         write_seqcount_end(&inode->i_size_seqcount);
691         preempt_enable();
692 #elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT)
693         preempt_disable();
694         inode->i_size = i_size;
695         preempt_enable();
696 #else
697         inode->i_size = i_size;
698 #endif
699 }
700 
701 /* Helper functions so that in most cases filesystems will
702  * not need to deal directly with kuid_t and kgid_t and can
703  * instead deal with the raw numeric values that are stored
704  * in the filesystem.
705  */
706 static inline uid_t i_uid_read(const struct inode *inode)
707 {
708         return from_kuid(&init_user_ns, inode->i_uid);
709 }
710 
711 static inline gid_t i_gid_read(const struct inode *inode)
712 {
713         return from_kgid(&init_user_ns, inode->i_gid);
714 }
715 
716 static inline void i_uid_write(struct inode *inode, uid_t uid)
717 {
718         inode->i_uid = make_kuid(&init_user_ns, uid);
719 }
720 
721 static inline void i_gid_write(struct inode *inode, gid_t gid)
722 {
723         inode->i_gid = make_kgid(&init_user_ns, gid);
724 }
725 
726 static inline unsigned iminor(const struct inode *inode)
727 {
728         return MINOR(inode->i_rdev);
729 }
730 
731 static inline unsigned imajor(const struct inode *inode)
732 {
733         return MAJOR(inode->i_rdev);
734 }
735 
736 extern struct block_device *I_BDEV(struct inode *inode);
737 
738 struct fown_struct {
739         rwlock_t lock;          /* protects pid, uid, euid fields */
740         struct pid *pid;        /* pid or -pgrp where SIGIO should be sent */
741         enum pid_type pid_type; /* Kind of process group SIGIO should be sent to */
742         kuid_t uid, euid;       /* uid/euid of process setting the owner */
743         int signum;             /* posix.1b rt signal to be delivered on IO */
744 };
745 
746 /*
747  * Track a single file's readahead state
748  */
749 struct file_ra_state {
750         pgoff_t start;                  /* where readahead started */
751         unsigned int size;              /* # of readahead pages */
752         unsigned int async_size;        /* do asynchronous readahead when
753                                            there are only # of pages ahead */
754 
755         unsigned int ra_pages;          /* Maximum readahead window */
756         unsigned int mmap_miss;         /* Cache miss stat for mmap accesses */
757         loff_t prev_pos;                /* Cache last read() position */
758 };
759 
760 /*
761  * Check if @index falls in the readahead windows.
762  */
763 static inline int ra_has_index(struct file_ra_state *ra, pgoff_t index)
764 {
765         return (index >= ra->start &&
766                 index <  ra->start + ra->size);
767 }
768 
769 #define FILE_MNT_WRITE_TAKEN    1
770 #define FILE_MNT_WRITE_RELEASED 2
771 
772 struct file {
773         union {
774                 struct llist_node       fu_llist;
775                 struct rcu_head         fu_rcuhead;
776         } f_u;
777         struct path             f_path;
778 #define f_dentry        f_path.dentry
779         struct inode            *f_inode;       /* cached value */
780         const struct file_operations    *f_op;
781 
782         /*
783          * Protects f_ep_links, f_flags, f_pos vs i_size in lseek SEEK_CUR.
784          * Must not be taken from IRQ context.
785          */
786         spinlock_t              f_lock;
787         atomic_long_t           f_count;
788         unsigned int            f_flags;
789         fmode_t                 f_mode;
790         loff_t                  f_pos;
791         struct fown_struct      f_owner;
792         const struct cred       *f_cred;
793         struct file_ra_state    f_ra;
794 
795         u64                     f_version;
796 #ifdef CONFIG_SECURITY
797         void                    *f_security;
798 #endif
799         /* needed for tty driver, and maybe others */
800         void                    *private_data;
801 
802 #ifdef CONFIG_EPOLL
803         /* Used by fs/eventpoll.c to link all the hooks to this file */
804         struct list_head        f_ep_links;
805         struct list_head        f_tfile_llink;
806 #endif /* #ifdef CONFIG_EPOLL */
807         struct address_space    *f_mapping;
808 #ifdef CONFIG_DEBUG_WRITECOUNT
809         unsigned long f_mnt_write_state;
810 #endif
811 };
812 
813 struct file_handle {
814         __u32 handle_bytes;
815         int handle_type;
816         /* file identifier */
817         unsigned char f_handle[0];
818 };
819 
820 static inline struct file *get_file(struct file *f)
821 {
822         atomic_long_inc(&f->f_count);
823         return f;
824 }
825 #define fput_atomic(x)  atomic_long_add_unless(&(x)->f_count, -1, 1)
826 #define file_count(x)   atomic_long_read(&(x)->f_count)
827 
828 #ifdef CONFIG_DEBUG_WRITECOUNT
829 static inline void file_take_write(struct file *f)
830 {
831         WARN_ON(f->f_mnt_write_state != 0);
832         f->f_mnt_write_state = FILE_MNT_WRITE_TAKEN;
833 }
834 static inline void file_release_write(struct file *f)
835 {
836         f->f_mnt_write_state |= FILE_MNT_WRITE_RELEASED;
837 }
838 static inline void file_reset_write(struct file *f)
839 {
840         f->f_mnt_write_state = 0;
841 }
842 static inline void file_check_state(struct file *f)
843 {
844         /*
845          * At this point, either both or neither of these bits
846          * should be set.
847          */
848         WARN_ON(f->f_mnt_write_state == FILE_MNT_WRITE_TAKEN);
849         WARN_ON(f->f_mnt_write_state == FILE_MNT_WRITE_RELEASED);
850 }
851 static inline int file_check_writeable(struct file *f)
852 {
853         if (f->f_mnt_write_state == FILE_MNT_WRITE_TAKEN)
854                 return 0;
855         printk(KERN_WARNING "writeable file with no "
856                             "mnt_want_write()\n");
857         WARN_ON(1);
858         return -EINVAL;
859 }
860 #else /* !CONFIG_DEBUG_WRITECOUNT */
861 static inline void file_take_write(struct file *filp) {}
862 static inline void file_release_write(struct file *filp) {}
863 static inline void file_reset_write(struct file *filp) {}
864 static inline void file_check_state(struct file *filp) {}
865 static inline int file_check_writeable(struct file *filp)
866 {
867         return 0;
868 }
869 #endif /* CONFIG_DEBUG_WRITECOUNT */
870 
871 #define MAX_NON_LFS     ((1UL<<31) - 1)
872 
873 /* Page cache limit. The filesystems should put that into their s_maxbytes 
874    limits, otherwise bad things can happen in VM. */ 
875 #if BITS_PER_LONG==32
876 #define MAX_LFS_FILESIZE        (((loff_t)PAGE_CACHE_SIZE << (BITS_PER_LONG-1))-1) 
877 #elif BITS_PER_LONG==64
878 #define MAX_LFS_FILESIZE        ((loff_t)0x7fffffffffffffffLL)
879 #endif
880 
881 #define FL_POSIX        1
882 #define FL_FLOCK        2
883 #define FL_DELEG        4       /* NFSv4 delegation */
884 #define FL_ACCESS       8       /* not trying to lock, just looking */
885 #define FL_EXISTS       16      /* when unlocking, test for existence */
886 #define FL_LEASE        32      /* lease held on this file */
887 #define FL_CLOSE        64      /* unlock on close */
888 #define FL_SLEEP        128     /* A blocking lock */
889 #define FL_DOWNGRADE_PENDING    256 /* Lease is being downgraded */
890 #define FL_UNLOCK_PENDING       512 /* Lease is being broken */
891 
892 /*
893  * Special return value from posix_lock_file() and vfs_lock_file() for
894  * asynchronous locking.
895  */
896 #define FILE_LOCK_DEFERRED 1
897 
898 /*
899  * The POSIX file lock owner is determined by
900  * the "struct files_struct" in the thread group
901  * (or NULL for no owner - BSD locks).
902  *
903  * Lockd stuffs a "host" pointer into this.
904  */
905 typedef struct files_struct *fl_owner_t;
906 
907 struct file_lock_operations {
908         void (*fl_copy_lock)(struct file_lock *, struct file_lock *);
909         void (*fl_release_private)(struct file_lock *);
910 };
911 
912 struct lock_manager_operations {
913         int (*lm_compare_owner)(struct file_lock *, struct file_lock *);
914         unsigned long (*lm_owner_key)(struct file_lock *);
915         void (*lm_notify)(struct file_lock *);  /* unblock callback */
916         int (*lm_grant)(struct file_lock *, struct file_lock *, int);
917         void (*lm_break)(struct file_lock *);
918         int (*lm_change)(struct file_lock **, int);
919 };
920 
921 struct lock_manager {
922         struct list_head list;
923 };
924 
925 struct net;
926 void locks_start_grace(struct net *, struct lock_manager *);
927 void locks_end_grace(struct lock_manager *);
928 int locks_in_grace(struct net *);
929 
930 /* that will die - we need it for nfs_lock_info */
931 #include <linux/nfs_fs_i.h>
932 
933 /*
934  * struct file_lock represents a generic "file lock". It's used to represent
935  * POSIX byte range locks, BSD (flock) locks, and leases. It's important to
936  * note that the same struct is used to represent both a request for a lock and
937  * the lock itself, but the same object is never used for both.
938  *
939  * FIXME: should we create a separate "struct lock_request" to help distinguish
940  * these two uses?
941  *
942  * The i_flock list is ordered by:
943  *
944  * 1) lock type -- FL_LEASEs first, then FL_FLOCK, and finally FL_POSIX
945  * 2) lock owner
946  * 3) lock range start
947  * 4) lock range end
948  *
949  * Obviously, the last two criteria only matter for POSIX locks.
950  */
951 struct file_lock {
952         struct file_lock *fl_next;      /* singly linked list for this inode  */
953         struct hlist_node fl_link;      /* node in global lists */
954         struct list_head fl_block;      /* circular list of blocked processes */
955         fl_owner_t fl_owner;
956         unsigned int fl_flags;
957         unsigned char fl_type;
958         unsigned int fl_pid;
959         int fl_link_cpu;                /* what cpu's list is this on? */
960         struct pid *fl_nspid;
961         wait_queue_head_t fl_wait;
962         struct file *fl_file;
963         loff_t fl_start;
964         loff_t fl_end;
965 
966         struct fasync_struct *  fl_fasync; /* for lease break notifications */
967         /* for lease breaks: */
968         unsigned long fl_break_time;
969         unsigned long fl_downgrade_time;
970 
971         const struct file_lock_operations *fl_ops;      /* Callbacks for filesystems */
972         const struct lock_manager_operations *fl_lmops; /* Callbacks for lockmanagers */
973         union {
974                 struct nfs_lock_info    nfs_fl;
975                 struct nfs4_lock_info   nfs4_fl;
976                 struct {
977                         struct list_head link;  /* link in AFS vnode's pending_locks list */
978                         int state;              /* state of grant or error if -ve */
979                 } afs;
980         } fl_u;
981 };
982 
983 /* The following constant reflects the upper bound of the file/locking space */
984 #ifndef OFFSET_MAX
985 #define INT_LIMIT(x)    (~((x)1 << (sizeof(x)*8 - 1)))
986 #define OFFSET_MAX      INT_LIMIT(loff_t)
987 #define OFFT_OFFSET_MAX INT_LIMIT(off_t)
988 #endif
989 
990 #include <linux/fcntl.h>
991 
992 extern void send_sigio(struct fown_struct *fown, int fd, int band);
993 
994 #ifdef CONFIG_FILE_LOCKING
995 extern int fcntl_getlk(struct file *, struct flock __user *);
996 extern int fcntl_setlk(unsigned int, struct file *, unsigned int,
997                         struct flock __user *);
998 
999 #if BITS_PER_LONG == 32
1000 extern int fcntl_getlk64(struct file *, struct flock64 __user *);
1001 extern int fcntl_setlk64(unsigned int, struct file *, unsigned int,
1002                         struct flock64 __user *);
1003 #endif
1004 
1005 extern int fcntl_setlease(unsigned int fd, struct file *filp, long arg);
1006 extern int fcntl_getlease(struct file *filp);
1007 
1008 /* fs/locks.c */
1009 void locks_free_lock(struct file_lock *fl);
1010 extern void locks_init_lock(struct file_lock *);
1011 extern struct file_lock * locks_alloc_lock(void);
1012 extern void locks_copy_lock(struct file_lock *, struct file_lock *);
1013 extern void __locks_copy_lock(struct file_lock *, const struct file_lock *);
1014 extern void locks_remove_posix(struct file *, fl_owner_t);
1015 extern void locks_remove_flock(struct file *);
1016 extern void locks_release_private(struct file_lock *);
1017 extern void posix_test_lock(struct file *, struct file_lock *);
1018 extern int posix_lock_file(struct file *, struct file_lock *, struct file_lock *);
1019 extern int posix_lock_file_wait(struct file *, struct file_lock *);
1020 extern int posix_unblock_lock(struct file_lock *);
1021 extern int vfs_test_lock(struct file *, struct file_lock *);
1022 extern int vfs_lock_file(struct file *, unsigned int, struct file_lock *, struct file_lock *);
1023 extern int vfs_cancel_lock(struct file *filp, struct file_lock *fl);
1024 extern int flock_lock_file_wait(struct file *filp, struct file_lock *fl);
1025 extern int __break_lease(struct inode *inode, unsigned int flags, unsigned int type);
1026 extern void lease_get_mtime(struct inode *, struct timespec *time);
1027 extern int generic_setlease(struct file *, long, struct file_lock **);
1028 extern int vfs_setlease(struct file *, long, struct file_lock **);
1029 extern int lease_modify(struct file_lock **, int);
1030 extern int lock_may_read(struct inode *, loff_t start, unsigned long count);
1031 extern int lock_may_write(struct inode *, loff_t start, unsigned long count);
1032 #else /* !CONFIG_FILE_LOCKING */
1033 static inline int fcntl_getlk(struct file *file, struct flock __user *user)
1034 {
1035         return -EINVAL;
1036 }
1037 
1038 static inline int fcntl_setlk(unsigned int fd, struct file *file,
1039                               unsigned int cmd, struct flock __user *user)
1040 {
1041         return -EACCES;
1042 }
1043 
1044 #if BITS_PER_LONG == 32
1045 static inline int fcntl_getlk64(struct file *file, struct flock64 __user *user)
1046 {
1047         return -EINVAL;
1048 }
1049 
1050 static inline int fcntl_setlk64(unsigned int fd, struct file *file,
1051                                 unsigned int cmd, struct flock64 __user *user)
1052 {
1053         return -EACCES;
1054 }
1055 #endif
1056 static inline int fcntl_setlease(unsigned int fd, struct file *filp, long arg)
1057 {
1058         return 0;
1059 }
1060 
1061 static inline int fcntl_getlease(struct file *filp)
1062 {
1063         return 0;
1064 }
1065 
1066 static inline void locks_init_lock(struct file_lock *fl)
1067 {
1068         return;
1069 }
1070 
1071 static inline void __locks_copy_lock(struct file_lock *new, struct file_lock *fl)
1072 {
1073         return;
1074 }
1075 
1076 static inline void locks_copy_lock(struct file_lock *new, struct file_lock *fl)
1077 {
1078         return;
1079 }
1080 
1081 static inline void locks_remove_posix(struct file *filp, fl_owner_t owner)
1082 {
1083         return;
1084 }
1085 
1086 static inline void locks_remove_flock(struct file *filp)
1087 {
1088         return;
1089 }
1090 
1091 static inline void posix_test_lock(struct file *filp, struct file_lock *fl)
1092 {
1093         return;
1094 }
1095 
1096 static inline int posix_lock_file(struct file *filp, struct file_lock *fl,
1097                                   struct file_lock *conflock)
1098 {
1099         return -ENOLCK;
1100 }
1101 
1102 static inline int posix_lock_file_wait(struct file *filp, struct file_lock *fl)
1103 {
1104         return -ENOLCK;
1105 }
1106 
1107 static inline int posix_unblock_lock(struct file_lock *waiter)
1108 {
1109         return -ENOENT;
1110 }
1111 
1112 static inline int vfs_test_lock(struct file *filp, struct file_lock *fl)
1113 {
1114         return 0;
1115 }
1116 
1117 static inline int vfs_lock_file(struct file *filp, unsigned int cmd,
1118                                 struct file_lock *fl, struct file_lock *conf)
1119 {
1120         return -ENOLCK;
1121 }
1122 
1123 static inline int vfs_cancel_lock(struct file *filp, struct file_lock *fl)
1124 {
1125         return 0;
1126 }
1127 
1128 static inline int flock_lock_file_wait(struct file *filp,
1129                                        struct file_lock *request)
1130 {
1131         return -ENOLCK;
1132 }
1133 
1134 static inline int __break_lease(struct inode *inode, unsigned int mode, unsigned int type)
1135 {
1136         return 0;
1137 }
1138 
1139 static inline void lease_get_mtime(struct inode *inode, struct timespec *time)
1140 {
1141         return;
1142 }
1143 
1144 static inline int generic_setlease(struct file *filp, long arg,
1145                                     struct file_lock **flp)
1146 {
1147         return -EINVAL;
1148 }
1149 
1150 static inline int vfs_setlease(struct file *filp, long arg,
1151                                struct file_lock **lease)
1152 {
1153         return -EINVAL;
1154 }
1155 
1156 static inline int lease_modify(struct file_lock **before, int arg)
1157 {
1158         return -EINVAL;
1159 }
1160 
1161 static inline int lock_may_read(struct inode *inode, loff_t start,
1162                                 unsigned long len)
1163 {
1164         return 1;
1165 }
1166 
1167 static inline int lock_may_write(struct inode *inode, loff_t start,
1168                                  unsigned long len)
1169 {
1170         return 1;
1171 }
1172 #endif /* !CONFIG_FILE_LOCKING */
1173 
1174 
1175 struct fasync_struct {
1176         spinlock_t              fa_lock;
1177         int                     magic;
1178         int                     fa_fd;
1179         struct fasync_struct    *fa_next; /* singly linked list */
1180         struct file             *fa_file;
1181         struct rcu_head         fa_rcu;
1182 };
1183 
1184 #define FASYNC_MAGIC 0x4601
1185 
1186 /* SMP safe fasync helpers: */
1187 extern int fasync_helper(int, struct file *, int, struct fasync_struct **);
1188 extern struct fasync_struct *fasync_insert_entry(int, struct file *, struct fasync_struct **, struct fasync_struct *);
1189 extern int fasync_remove_entry(struct file *, struct fasync_struct **);
1190 extern struct fasync_struct *fasync_alloc(void);
1191 extern void fasync_free(struct fasync_struct *);
1192 
1193 /* can be called from interrupts */
1194 extern void kill_fasync(struct fasync_struct **, int, int);
1195 
1196 extern int __f_setown(struct file *filp, struct pid *, enum pid_type, int force);
1197 extern int f_setown(struct file *filp, unsigned long arg, int force);
1198 extern void f_delown(struct file *filp);
1199 extern pid_t f_getown(struct file *filp);
1200 extern int send_sigurg(struct fown_struct *fown);
1201 
1202 struct mm_struct;
1203 
1204 /*
1205  *      Umount options
1206  */
1207 
1208 #define MNT_FORCE       0x00000001      /* Attempt to forcibily umount */
1209 #define MNT_DETACH      0x00000002      /* Just detach from the tree */
1210 #define MNT_EXPIRE      0x00000004      /* Mark for expiry */
1211 #define UMOUNT_NOFOLLOW 0x00000008      /* Don't follow symlink on umount */
1212 #define UMOUNT_UNUSED   0x80000000      /* Flag guaranteed to be unused */
1213 
1214 extern struct list_head super_blocks;
1215 extern spinlock_t sb_lock;
1216 
1217 /* Possible states of 'frozen' field */
1218 enum {
1219         SB_UNFROZEN = 0,                /* FS is unfrozen */
1220         SB_FREEZE_WRITE = 1,            /* Writes, dir ops, ioctls frozen */
1221         SB_FREEZE_PAGEFAULT = 2,        /* Page faults stopped as well */
1222         SB_FREEZE_FS = 3,               /* For internal FS use (e.g. to stop
1223                                          * internal threads if needed) */
1224         SB_FREEZE_COMPLETE = 4,         /* ->freeze_fs finished successfully */
1225 };
1226 
1227 #define SB_FREEZE_LEVELS (SB_FREEZE_COMPLETE - 1)
1228 
1229 struct sb_writers {
1230         /* Counters for counting writers at each level */
1231         struct percpu_counter   counter[SB_FREEZE_LEVELS];
1232         wait_queue_head_t       wait;           /* queue for waiting for
1233                                                    writers / faults to finish */
1234         int                     frozen;         /* Is sb frozen? */
1235         wait_queue_head_t       wait_unfrozen;  /* queue for waiting for
1236                                                    sb to be thawed */
1237 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1238         struct lockdep_map      lock_map[SB_FREEZE_LEVELS];
1239 #endif
1240 };
1241 
1242 struct super_block {
1243         struct list_head        s_list;         /* Keep this first */
1244         dev_t                   s_dev;          /* search index; _not_ kdev_t */
1245         unsigned char           s_blocksize_bits;
1246         unsigned long           s_blocksize;
1247         loff_t                  s_maxbytes;     /* Max file size */
1248         struct file_system_type *s_type;
1249         const struct super_operations   *s_op;
1250         const struct dquot_operations   *dq_op;
1251         const struct quotactl_ops       *s_qcop;
1252         const struct export_operations *s_export_op;
1253         unsigned long           s_flags;
1254         unsigned long           s_magic;
1255         struct dentry           *s_root;
1256         struct rw_semaphore     s_umount;
1257         int                     s_count;
1258         atomic_t                s_active;
1259 #ifdef CONFIG_SECURITY
1260         void                    *s_security;
1261 #endif
1262         const struct xattr_handler **s_xattr;
1263 
1264         struct list_head        s_inodes;       /* all inodes */
1265         struct hlist_bl_head    s_anon;         /* anonymous dentries for (nfs) exporting */
1266         struct list_head        s_mounts;       /* list of mounts; _not_ for fs use */
1267         struct block_device     *s_bdev;
1268         struct backing_dev_info *s_bdi;
1269         struct mtd_info         *s_mtd;
1270         struct hlist_node       s_instances;
1271         struct quota_info       s_dquot;        /* Diskquota specific options */
1272 
1273         struct sb_writers       s_writers;
1274 
1275         char s_id[32];                          /* Informational name */
1276         u8 s_uuid[16];                          /* UUID */
1277 
1278         void                    *s_fs_info;     /* Filesystem private info */
1279         unsigned int            s_max_links;
1280         fmode_t                 s_mode;
1281 
1282         /* Granularity of c/m/atime in ns.
1283            Cannot be worse than a second */
1284         u32                s_time_gran;
1285 
1286         /*
1287          * The next field is for VFS *only*. No filesystems have any business
1288          * even looking at it. You had been warned.
1289          */
1290         struct mutex s_vfs_rename_mutex;        /* Kludge */
1291 
1292         /*
1293          * Filesystem subtype.  If non-empty the filesystem type field
1294          * in /proc/mounts will be "type.subtype"
1295          */
1296         char *s_subtype;
1297 
1298         /*
1299          * Saved mount options for lazy filesystems using
1300          * generic_show_options()
1301          */
1302         char __rcu *s_options;
1303         const struct dentry_operations *s_d_op; /* default d_op for dentries */
1304 
1305         /*
1306          * Saved pool identifier for cleancache (-1 means none)
1307          */
1308         int cleancache_poolid;
1309 
1310         struct shrinker s_shrink;       /* per-sb shrinker handle */
1311 
1312         /* Number of inodes with nlink == 0 but still referenced */
1313         atomic_long_t s_remove_count;
1314 
1315         /* Being remounted read-only */
1316         int s_readonly_remount;
1317 
1318         /* AIO completions deferred from interrupt context */
1319         struct workqueue_struct *s_dio_done_wq;
1320 
1321         /*
1322          * Keep the lru lists last in the structure so they always sit on their
1323          * own individual cachelines.
1324          */
1325         struct list_lru         s_dentry_lru ____cacheline_aligned_in_smp;
1326         struct list_lru         s_inode_lru ____cacheline_aligned_in_smp;
1327         struct rcu_head         rcu;
1328 };
1329 
1330 extern struct timespec current_fs_time(struct super_block *sb);
1331 
1332 /*
1333  * Snapshotting support.
1334  */
1335 
1336 void __sb_end_write(struct super_block *sb, int level);
1337 int __sb_start_write(struct super_block *sb, int level, bool wait);
1338 
1339 /**
1340  * sb_end_write - drop write access to a superblock
1341  * @sb: the super we wrote to
1342  *
1343  * Decrement number of writers to the filesystem. Wake up possible waiters
1344  * wanting to freeze the filesystem.
1345  */
1346 static inline void sb_end_write(struct super_block *sb)
1347 {
1348         __sb_end_write(sb, SB_FREEZE_WRITE);
1349 }
1350 
1351 /**
1352  * sb_end_pagefault - drop write access to a superblock from a page fault
1353  * @sb: the super we wrote to
1354  *
1355  * Decrement number of processes handling write page fault to the filesystem.
1356  * Wake up possible waiters wanting to freeze the filesystem.
1357  */
1358 static inline void sb_end_pagefault(struct super_block *sb)
1359 {
1360         __sb_end_write(sb, SB_FREEZE_PAGEFAULT);
1361 }
1362 
1363 /**
1364  * sb_end_intwrite - drop write access to a superblock for internal fs purposes
1365  * @sb: the super we wrote to
1366  *
1367  * Decrement fs-internal number of writers to the filesystem.  Wake up possible
1368  * waiters wanting to freeze the filesystem.
1369  */
1370 static inline void sb_end_intwrite(struct super_block *sb)
1371 {
1372         __sb_end_write(sb, SB_FREEZE_FS);
1373 }
1374 
1375 /**
1376  * sb_start_write - get write access to a superblock
1377  * @sb: the super we write to
1378  *
1379  * When a process wants to write data or metadata to a file system (i.e. dirty
1380  * a page or an inode), it should embed the operation in a sb_start_write() -
1381  * sb_end_write() pair to get exclusion against file system freezing. This
1382  * function increments number of writers preventing freezing. If the file
1383  * system is already frozen, the function waits until the file system is
1384  * thawed.
1385  *
1386  * Since freeze protection behaves as a lock, users have to preserve
1387  * ordering of freeze protection and other filesystem locks. Generally,
1388  * freeze protection should be the outermost lock. In particular, we have:
1389  *
1390  * sb_start_write
1391  *   -> i_mutex                 (write path, truncate, directory ops, ...)
1392  *   -> s_umount                (freeze_super, thaw_super)
1393  */
1394 static inline void sb_start_write(struct super_block *sb)
1395 {
1396         __sb_start_write(sb, SB_FREEZE_WRITE, true);
1397 }
1398 
1399 static inline int sb_start_write_trylock(struct super_block *sb)
1400 {
1401         return __sb_start_write(sb, SB_FREEZE_WRITE, false);
1402 }
1403 
1404 /**
1405  * sb_start_pagefault - get write access to a superblock from a page fault
1406  * @sb: the super we write to
1407  *
1408  * When a process starts handling write page fault, it should embed the
1409  * operation into sb_start_pagefault() - sb_end_pagefault() pair to get
1410  * exclusion against file system freezing. This is needed since the page fault
1411  * is going to dirty a page. This function increments number of running page
1412  * faults preventing freezing. If the file system is already frozen, the
1413  * function waits until the file system is thawed.
1414  *
1415  * Since page fault freeze protection behaves as a lock, users have to preserve
1416  * ordering of freeze protection and other filesystem locks. It is advised to
1417  * put sb_start_pagefault() close to mmap_sem in lock ordering. Page fault
1418  * handling code implies lock dependency:
1419  *
1420  * mmap_sem
1421  *   -> sb_start_pagefault
1422  */
1423 static inline void sb_start_pagefault(struct super_block *sb)
1424 {
1425         __sb_start_write(sb, SB_FREEZE_PAGEFAULT, true);
1426 }
1427 
1428 /*
1429  * sb_start_intwrite - get write access to a superblock for internal fs purposes
1430  * @sb: the super we write to
1431  *
1432  * This is the third level of protection against filesystem freezing. It is
1433  * free for use by a filesystem. The only requirement is that it must rank
1434  * below sb_start_pagefault.
1435  *
1436  * For example filesystem can call sb_start_intwrite() when starting a
1437  * transaction which somewhat eases handling of freezing for internal sources
1438  * of filesystem changes (internal fs threads, discarding preallocation on file
1439  * close, etc.).
1440  */
1441 static inline void sb_start_intwrite(struct super_block *sb)
1442 {
1443         __sb_start_write(sb, SB_FREEZE_FS, true);
1444 }
1445 
1446 
1447 extern bool inode_owner_or_capable(const struct inode *inode);
1448 
1449 /*
1450  * VFS helper functions..
1451  */
1452 extern int vfs_create(struct inode *, struct dentry *, umode_t, bool);
1453 extern int vfs_mkdir(struct inode *, struct dentry *, umode_t);
1454 extern int vfs_mknod(struct inode *, struct dentry *, umode_t, dev_t);
1455 extern int vfs_symlink(struct inode *, struct dentry *, const char *);
1456 extern int vfs_link(struct dentry *, struct inode *, struct dentry *, struct inode **);
1457 extern int vfs_rmdir(struct inode *, struct dentry *);
1458 extern int vfs_unlink(struct inode *, struct dentry *, struct inode **);
1459 extern int vfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *, struct inode **);
1460 
1461 /*
1462  * VFS dentry helper functions.
1463  */
1464 extern void dentry_unhash(struct dentry *dentry);
1465 
1466 /*
1467  * VFS file helper functions.
1468  */
1469 extern void inode_init_owner(struct inode *inode, const struct inode *dir,
1470                         umode_t mode);
1471 /*
1472  * VFS FS_IOC_FIEMAP helper definitions.
1473  */
1474 struct fiemap_extent_info {
1475         unsigned int fi_flags;          /* Flags as passed from user */
1476         unsigned int fi_extents_mapped; /* Number of mapped extents */
1477         unsigned int fi_extents_max;    /* Size of fiemap_extent array */
1478         struct fiemap_extent __user *fi_extents_start; /* Start of
1479                                                         fiemap_extent array */
1480 };
1481 int fiemap_fill_next_extent(struct fiemap_extent_info *info, u64 logical,
1482                             u64 phys, u64 len, u32 flags);
1483 int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags);
1484 
1485 /*
1486  * File types
1487  *
1488  * NOTE! These match bits 12..15 of stat.st_mode
1489  * (ie "(i_mode >> 12) & 15").
1490  */
1491 #define DT_UNKNOWN      0
1492 #define DT_FIFO         1
1493 #define DT_CHR          2
1494 #define DT_DIR          4
1495 #define DT_BLK          6
1496 #define DT_REG          8
1497 #define DT_LNK          10
1498 #define DT_SOCK         12
1499 #define DT_WHT          14
1500 
1501 /*
1502  * This is the "filldir" function type, used by readdir() to let
1503  * the kernel specify what kind of dirent layout it wants to have.
1504  * This allows the kernel to read directories into kernel space or
1505  * to have different dirent layouts depending on the binary type.
1506  */
1507 typedef int (*filldir_t)(void *, const char *, int, loff_t, u64, unsigned);
1508 struct dir_context {
1509         const filldir_t actor;
1510         loff_t pos;
1511 };
1512 
1513 struct block_device_operations;
1514 
1515 /* These macros are for out of kernel modules to test that
1516  * the kernel supports the unlocked_ioctl and compat_ioctl
1517  * fields in struct file_operations. */
1518 #define HAVE_COMPAT_IOCTL 1
1519 #define HAVE_UNLOCKED_IOCTL 1
1520 
1521 struct file_operations {
1522         struct module *owner;
1523         loff_t (*llseek) (struct file *, loff_t, int);
1524         ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
1525         ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
1526         ssize_t (*aio_read) (struct kiocb *, const struct iovec *, unsigned long, loff_t);
1527         ssize_t (*aio_write) (struct kiocb *, const struct iovec *, unsigned long, loff_t);
1528         int (*iterate) (struct file *, struct dir_context *);
1529         unsigned int (*poll) (struct file *, struct poll_table_struct *);
1530         long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
1531         long (*compat_ioctl) (struct file *, unsigned int, unsigned long);
1532         int (*mmap) (struct file *, struct vm_area_struct *);
1533         int (*open) (struct inode *, struct file *);
1534         int (*flush) (struct file *, fl_owner_t id);
1535         int (*release) (struct inode *, struct file *);
1536         int (*fsync) (struct file *, loff_t, loff_t, int datasync);
1537         int (*aio_fsync) (struct kiocb *, int datasync);
1538         int (*fasync) (int, struct file *, int);
1539         int (*lock) (struct file *, int, struct file_lock *);
1540         ssize_t (*sendpage) (struct file *, struct page *, int, size_t, loff_t *, int);
1541         unsigned long (*get_unmapped_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
1542         int (*check_flags)(int);
1543         int (*flock) (struct file *, int, struct file_lock *);
1544         ssize_t (*splice_write)(struct pipe_inode_info *, struct file *, loff_t *, size_t, unsigned int);
1545         ssize_t (*splice_read)(struct file *, loff_t *, struct pipe_inode_info *, size_t, unsigned int);
1546         int (*setlease)(struct file *, long, struct file_lock **);
1547         long (*fallocate)(struct file *file, int mode, loff_t offset,
1548                           loff_t len);
1549         int (*show_fdinfo)(struct seq_file *m, struct file *f);
1550 };
1551 
1552 struct inode_operations {
1553         struct dentry * (*lookup) (struct inode *,struct dentry *, unsigned int);
1554         void * (*follow_link) (struct dentry *, struct nameidata *);
1555         int (*permission) (struct inode *, int);
1556         struct posix_acl * (*get_acl)(struct inode *, int);
1557 
1558         int (*readlink) (struct dentry *, char __user *,int);
1559         void (*put_link) (struct dentry *, struct nameidata *, void *);
1560 
1561         int (*create) (struct inode *,struct dentry *, umode_t, bool);
1562         int (*link) (struct dentry *,struct inode *,struct dentry *);
1563         int (*unlink) (struct inode *,struct dentry *);
1564         int (*symlink) (struct inode *,struct dentry *,const char *);
1565         int (*mkdir) (struct inode *,struct dentry *,umode_t);
1566         int (*rmdir) (struct inode *,struct dentry *);
1567         int (*mknod) (struct inode *,struct dentry *,umode_t,dev_t);
1568         int (*rename) (struct inode *, struct dentry *,
1569                         struct inode *, struct dentry *);
1570         int (*setattr) (struct dentry *, struct iattr *);
1571         int (*getattr) (struct vfsmount *mnt, struct dentry *, struct kstat *);
1572         int (*setxattr) (struct dentry *, const char *,const void *,size_t,int);
1573         ssize_t (*getxattr) (struct dentry *, const char *, void *, size_t);
1574         ssize_t (*listxattr) (struct dentry *, char *, size_t);
1575         int (*removexattr) (struct dentry *, const char *);
1576         int (*fiemap)(struct inode *, struct fiemap_extent_info *, u64 start,
1577                       u64 len);
1578         int (*update_time)(struct inode *, struct timespec *, int);
1579         int (*atomic_open)(struct inode *, struct dentry *,
1580                            struct file *, unsigned open_flag,
1581                            umode_t create_mode, int *opened);
1582         int (*tmpfile) (struct inode *, struct dentry *, umode_t);
1583 } ____cacheline_aligned;
1584 
1585 ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector,
1586                               unsigned long nr_segs, unsigned long fast_segs,
1587                               struct iovec *fast_pointer,
1588                               struct iovec **ret_pointer);
1589 
1590 extern ssize_t vfs_read(struct file *, char __user *, size_t, loff_t *);
1591 extern ssize_t vfs_write(struct file *, const char __user *, size_t, loff_t *);
1592 extern ssize_t vfs_readv(struct file *, const struct iovec __user *,
1593                 unsigned long, loff_t *);
1594 extern ssize_t vfs_writev(struct file *, const struct iovec __user *,
1595                 unsigned long, loff_t *);
1596 
1597 struct super_operations {
1598         struct inode *(*alloc_inode)(struct super_block *sb);
1599         void (*destroy_inode)(struct inode *);
1600 
1601         void (*dirty_inode) (struct inode *, int flags);
1602         int (*write_inode) (struct inode *, struct writeback_control *wbc);
1603         int (*drop_inode) (struct inode *);
1604         void (*evict_inode) (struct inode *);
1605         void (*put_super) (struct super_block *);
1606         int (*sync_fs)(struct super_block *sb, int wait);
1607         int (*freeze_fs) (struct super_block *);
1608         int (*unfreeze_fs) (struct super_block *);
1609         int (*statfs) (struct dentry *, struct kstatfs *);
1610         int (*remount_fs) (struct super_block *, int *, char *);
1611         void (*umount_begin) (struct super_block *);
1612 
1613         int (*show_options)(struct seq_file *, struct dentry *);
1614         int (*show_devname)(struct seq_file *, struct dentry *);
1615         int (*show_path)(struct seq_file *, struct dentry *);
1616         int (*show_stats)(struct seq_file *, struct dentry *);
1617 #ifdef CONFIG_QUOTA
1618         ssize_t (*quota_read)(struct super_block *, int, char *, size_t, loff_t);
1619         ssize_t (*quota_write)(struct super_block *, int, const char *, size_t, loff_t);
1620 #endif
1621         int (*bdev_try_to_free_page)(struct super_block*, struct page*, gfp_t);
1622         long (*nr_cached_objects)(struct super_block *, int);
1623         long (*free_cached_objects)(struct super_block *, long, int);
1624 };
1625 
1626 /*
1627  * Inode flags - they have no relation to superblock flags now
1628  */
1629 #define S_SYNC          1       /* Writes are synced at once */
1630 #define S_NOATIME       2       /* Do not update access times */
1631 #define S_APPEND        4       /* Append-only file */
1632 #define S_IMMUTABLE     8       /* Immutable file */
1633 #define S_DEAD          16      /* removed, but still open directory */
1634 #define S_NOQUOTA       32      /* Inode is not counted to quota */
1635 #define S_DIRSYNC       64      /* Directory modifications are synchronous */
1636 #define S_NOCMTIME      128     /* Do not update file c/mtime */
1637 #define S_SWAPFILE      256     /* Do not truncate: swapon got its bmaps */
1638 #define S_PRIVATE       512     /* Inode is fs-internal */
1639 #define S_IMA           1024    /* Inode has an associated IMA struct */
1640 #define S_AUTOMOUNT     2048    /* Automount/referral quasi-directory */
1641 #define S_NOSEC         4096    /* no suid or xattr security attributes */
1642 
1643 /*
1644  * Note that nosuid etc flags are inode-specific: setting some file-system
1645  * flags just means all the inodes inherit those flags by default. It might be
1646  * possible to override it selectively if you really wanted to with some
1647  * ioctl() that is not currently implemented.
1648  *
1649  * Exception: MS_RDONLY is always applied to the entire file system.
1650  *
1651  * Unfortunately, it is possible to change a filesystems flags with it mounted
1652  * with files in use.  This means that all of the inodes will not have their
1653  * i_flags updated.  Hence, i_flags no longer inherit the superblock mount
1654  * flags, so these have to be checked separately. -- rmk@arm.uk.linux.org
1655  */
1656 #define __IS_FLG(inode, flg)    ((inode)->i_sb->s_flags & (flg))
1657 
1658 #define IS_RDONLY(inode)        ((inode)->i_sb->s_flags & MS_RDONLY)
1659 #define IS_SYNC(inode)          (__IS_FLG(inode, MS_SYNCHRONOUS) || \
1660                                         ((inode)->i_flags & S_SYNC))
1661 #define IS_DIRSYNC(inode)       (__IS_FLG(inode, MS_SYNCHRONOUS|MS_DIRSYNC) || \
1662                                         ((inode)->i_flags & (S_SYNC|S_DIRSYNC)))
1663 #define IS_MANDLOCK(inode)      __IS_FLG(inode, MS_MANDLOCK)
1664 #define IS_NOATIME(inode)       __IS_FLG(inode, MS_RDONLY|MS_NOATIME)
1665 #define IS_I_VERSION(inode)     __IS_FLG(inode, MS_I_VERSION)
1666 
1667 #define IS_NOQUOTA(inode)       ((inode)->i_flags & S_NOQUOTA)
1668 #define IS_APPEND(inode)        ((inode)->i_flags & S_APPEND)
1669 #define IS_IMMUTABLE(inode)     ((inode)->i_flags & S_IMMUTABLE)
1670 #define IS_POSIXACL(inode)      __IS_FLG(inode, MS_POSIXACL)
1671 
1672 #define IS_DEADDIR(inode)       ((inode)->i_flags & S_DEAD)
1673 #define IS_NOCMTIME(inode)      ((inode)->i_flags & S_NOCMTIME)
1674 #define IS_SWAPFILE(inode)      ((inode)->i_flags & S_SWAPFILE)
1675 #define IS_PRIVATE(inode)       ((inode)->i_flags & S_PRIVATE)
1676 #define IS_IMA(inode)           ((inode)->i_flags & S_IMA)
1677 #define IS_AUTOMOUNT(inode)     ((inode)->i_flags & S_AUTOMOUNT)
1678 #define IS_NOSEC(inode)         ((inode)->i_flags & S_NOSEC)
1679 
1680 /*
1681  * Inode state bits.  Protected by inode->i_lock
1682  *
1683  * Three bits determine the dirty state of the inode, I_DIRTY_SYNC,
1684  * I_DIRTY_DATASYNC and I_DIRTY_PAGES.
1685  *
1686  * Four bits define the lifetime of an inode.  Initially, inodes are I_NEW,
1687  * until that flag is cleared.  I_WILL_FREE, I_FREEING and I_CLEAR are set at
1688  * various stages of removing an inode.
1689  *
1690  * Two bits are used for locking and completion notification, I_NEW and I_SYNC.
1691  *
1692  * I_DIRTY_SYNC         Inode is dirty, but doesn't have to be written on
1693  *                      fdatasync().  i_atime is the usual cause.
1694  * I_DIRTY_DATASYNC     Data-related inode changes pending. We keep track of
1695  *                      these changes separately from I_DIRTY_SYNC so that we
1696  *                      don't have to write inode on fdatasync() when only
1697  *                      mtime has changed in it.
1698  * I_DIRTY_PAGES        Inode has dirty pages.  Inode itself may be clean.
1699  * I_NEW                Serves as both a mutex and completion notification.
1700  *                      New inodes set I_NEW.  If two processes both create
1701  *                      the same inode, one of them will release its inode and
1702  *                      wait for I_NEW to be released before returning.
1703  *                      Inodes in I_WILL_FREE, I_FREEING or I_CLEAR state can
1704  *                      also cause waiting on I_NEW, without I_NEW actually
1705  *                      being set.  find_inode() uses this to prevent returning
1706  *                      nearly-dead inodes.
1707  * I_WILL_FREE          Must be set when calling write_inode_now() if i_count
1708  *                      is zero.  I_FREEING must be set when I_WILL_FREE is
1709  *                      cleared.
1710  * I_FREEING            Set when inode is about to be freed but still has dirty
1711  *                      pages or buffers attached or the inode itself is still
1712  *                      dirty.
1713  * I_CLEAR              Added by clear_inode().  In this state the inode is
1714  *                      clean and can be destroyed.  Inode keeps I_FREEING.
1715  *
1716  *                      Inodes that are I_WILL_FREE, I_FREEING or I_CLEAR are
1717  *                      prohibited for many purposes.  iget() must wait for
1718  *                      the inode to be completely released, then create it
1719  *                      anew.  Other functions will just ignore such inodes,
1720  *                      if appropriate.  I_NEW is used for waiting.
1721  *
1722  * I_SYNC               Writeback of inode is running. The bit is set during
1723  *                      data writeback, and cleared with a wakeup on the bit
1724  *                      address once it is done. The bit is also used to pin
1725  *                      the inode in memory for flusher thread.
1726  *
1727  * I_REFERENCED         Marks the inode as recently references on the LRU list.
1728  *
1729  * I_DIO_WAKEUP         Never set.  Only used as a key for wait_on_bit().
1730  *
1731  * Q: What is the difference between I_WILL_FREE and I_FREEING?
1732  */
1733 #define I_DIRTY_SYNC            (1 << 0)
1734 #define I_DIRTY_DATASYNC        (1 << 1)
1735 #define I_DIRTY_PAGES           (1 << 2)
1736 #define __I_NEW                 3
1737 #define I_NEW                   (1 << __I_NEW)
1738 #define I_WILL_FREE             (1 << 4)
1739 #define I_FREEING               (1 << 5)
1740 #define I_CLEAR                 (1 << 6)
1741 #define __I_SYNC                7
1742 #define I_SYNC                  (1 << __I_SYNC)
1743 #define I_REFERENCED            (1 << 8)
1744 #define __I_DIO_WAKEUP          9
1745 #define I_DIO_WAKEUP            (1 << I_DIO_WAKEUP)
1746 #define I_LINKABLE              (1 << 10)
1747 
1748 #define I_DIRTY (I_DIRTY_SYNC | I_DIRTY_DATASYNC | I_DIRTY_PAGES)
1749 
1750 extern void __mark_inode_dirty(struct inode *, int);
1751 static inline void mark_inode_dirty(struct inode *inode)
1752 {
1753         __mark_inode_dirty(inode, I_DIRTY);
1754 }
1755 
1756 static inline void mark_inode_dirty_sync(struct inode *inode)
1757 {
1758         __mark_inode_dirty(inode, I_DIRTY_SYNC);
1759 }
1760 
1761 extern void inc_nlink(struct inode *inode);
1762 extern void drop_nlink(struct inode *inode);
1763 extern void clear_nlink(struct inode *inode);
1764 extern void set_nlink(struct inode *inode, unsigned int nlink);
1765 
1766 static inline void inode_inc_link_count(struct inode *inode)
1767 {
1768         inc_nlink(inode);
1769         mark_inode_dirty(inode);
1770 }
1771 
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 
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 enum file_time_flags {
1794         S_ATIME = 1,
1795         S_MTIME = 2,
1796         S_CTIME = 4,
1797         S_VERSION = 8,
1798 };
1799 
1800 extern void touch_atime(const struct path *);
1801 static inline void file_accessed(struct file *file)
1802 {
1803         if (!(file->f_flags & O_NOATIME))
1804                 touch_atime(&file->f_path);
1805 }
1806 
1807 int sync_inode(struct inode *inode, struct writeback_control *wbc);
1808 int sync_inode_metadata(struct inode *inode, int wait);
1809 
1810 struct file_system_type {
1811         const char *name;
1812         int fs_flags;
1813 #define FS_REQUIRES_DEV         1 
1814 #define FS_BINARY_MOUNTDATA     2
1815 #define FS_HAS_SUBTYPE          4
1816 #define FS_USERNS_MOUNT         8       /* Can be mounted by userns root */
1817 #define FS_USERNS_DEV_MOUNT     16 /* A userns mount does not imply MNT_NODEV */
1818 #define FS_RENAME_DOES_D_MOVE   32768   /* FS will handle d_move() during rename() internally. */
1819         struct dentry *(*mount) (struct file_system_type *, int,
1820                        const char *, void *);
1821         void (*kill_sb) (struct super_block *);
1822         struct module *owner;
1823         struct file_system_type * next;
1824         struct hlist_head fs_supers;
1825 
1826         struct lock_class_key s_lock_key;
1827         struct lock_class_key s_umount_key;
1828         struct lock_class_key s_vfs_rename_key;
1829         struct lock_class_key s_writers_key[SB_FREEZE_LEVELS];
1830 
1831         struct lock_class_key i_lock_key;
1832         struct lock_class_key i_mutex_key;
1833         struct lock_class_key i_mutex_dir_key;
1834 };
1835 
1836 #define MODULE_ALIAS_FS(NAME) MODULE_ALIAS("fs-" NAME)
1837 
1838 extern struct dentry *mount_ns(struct file_system_type *fs_type, int flags,
1839         void *data, int (*fill_super)(struct super_block *, void *, int));
1840 extern struct dentry *mount_bdev(struct file_system_type *fs_type,
1841         int flags, const char *dev_name, void *data,
1842         int (*fill_super)(struct super_block *, void *, int));
1843 extern struct dentry *mount_single(struct file_system_type *fs_type,
1844         int flags, void *data,
1845         int (*fill_super)(struct super_block *, void *, int));
1846 extern struct dentry *mount_nodev(struct file_system_type *fs_type,
1847         int flags, void *data,
1848         int (*fill_super)(struct super_block *, void *, int));
1849 extern struct dentry *mount_subtree(struct vfsmount *mnt, const char *path);
1850 void generic_shutdown_super(struct super_block *sb);
1851 void kill_block_super(struct super_block *sb);
1852 void kill_anon_super(struct super_block *sb);
1853 void kill_litter_super(struct super_block *sb);
1854 void deactivate_super(struct super_block *sb);
1855 void deactivate_locked_super(struct super_block *sb);
1856 int set_anon_super(struct super_block *s, void *data);
1857 int get_anon_bdev(dev_t *);
1858 void free_anon_bdev(dev_t);
1859 struct super_block *sget(struct file_system_type *type,
1860                         int (*test)(struct super_block *,void *),
1861                         int (*set)(struct super_block *,void *),
1862                         int flags, void *data);
1863 extern struct dentry *mount_pseudo(struct file_system_type *, char *,
1864         const struct super_operations *ops,
1865         const struct dentry_operations *dops,
1866         unsigned long);
1867 
1868 /* Alas, no aliases. Too much hassle with bringing module.h everywhere */
1869 #define fops_get(fops) \
1870         (((fops) && try_module_get((fops)->owner) ? (fops) : NULL))
1871 #define fops_put(fops) \
1872         do { if (fops) module_put((fops)->owner); } while(0)
1873 /*
1874  * This one is to be used *ONLY* from ->open() instances.
1875  * fops must be non-NULL, pinned down *and* module dependencies
1876  * should be sufficient to pin the caller down as well.
1877  */
1878 #define replace_fops(f, fops) \
1879         do {    \
1880                 struct file *__file = (f); \
1881                 fops_put(__file->f_op); \
1882                 BUG_ON(!(__file->f_op = (fops))); \
1883         } while(0)
1884 
1885 extern int register_filesystem(struct file_system_type *);
1886 extern int unregister_filesystem(struct file_system_type *);
1887 extern struct vfsmount *kern_mount_data(struct file_system_type *, void *data);
1888 #define kern_mount(type) kern_mount_data(type, NULL)
1889 extern void kern_unmount(struct vfsmount *mnt);
1890 extern int may_umount_tree(struct vfsmount *);
1891 extern int may_umount(struct vfsmount *);
1892 extern long do_mount(const char *, const char *, const char *, unsigned long, void *);
1893 extern struct vfsmount *collect_mounts(struct path *);
1894 extern void drop_collected_mounts(struct vfsmount *);
1895 extern int iterate_mounts(int (*)(struct vfsmount *, void *), void *,
1896                           struct vfsmount *);
1897 extern int vfs_statfs(struct path *, struct kstatfs *);
1898 extern int user_statfs(const char __user *, struct kstatfs *);
1899 extern int fd_statfs(int, struct kstatfs *);
1900 extern int vfs_ustat(dev_t, struct kstatfs *);
1901 extern int freeze_super(struct super_block *super);
1902 extern int thaw_super(struct super_block *super);
1903 extern bool our_mnt(struct vfsmount *mnt);
1904 extern bool fs_fully_visible(struct file_system_type *);
1905 
1906 extern int current_umask(void);
1907 
1908 extern void ihold(struct inode * inode);
1909 extern void iput(struct inode *);
1910 
1911 /* /sys/fs */
1912 extern struct kobject *fs_kobj;
1913 
1914 #define MAX_RW_COUNT (INT_MAX & PAGE_CACHE_MASK)
1915 
1916 #define FLOCK_VERIFY_READ  1
1917 #define FLOCK_VERIFY_WRITE 2
1918 
1919 #ifdef CONFIG_FILE_LOCKING
1920 extern int locks_mandatory_locked(struct inode *);
1921 extern int locks_mandatory_area(int, struct inode *, struct file *, loff_t, size_t);
1922 
1923 /*
1924  * Candidates for mandatory locking have the setgid bit set
1925  * but no group execute bit -  an otherwise meaningless combination.
1926  */
1927 
1928 static inline int __mandatory_lock(struct inode *ino)
1929 {
1930         return (ino->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID;
1931 }
1932 
1933 /*
1934  * ... and these candidates should be on MS_MANDLOCK mounted fs,
1935  * otherwise these will be advisory locks
1936  */
1937 
1938 static inline int mandatory_lock(struct inode *ino)
1939 {
1940         return IS_MANDLOCK(ino) && __mandatory_lock(ino);
1941 }
1942 
1943 static inline int locks_verify_locked(struct inode *inode)
1944 {
1945         if (mandatory_lock(inode))
1946                 return locks_mandatory_locked(inode);
1947         return 0;
1948 }
1949 
1950 static inline int locks_verify_truncate(struct inode *inode,
1951                                     struct file *filp,
1952                                     loff_t size)
1953 {
1954         if (inode->i_flock && mandatory_lock(inode))
1955                 return locks_mandatory_area(
1956                         FLOCK_VERIFY_WRITE, inode, filp,
1957                         size < inode->i_size ? size : inode->i_size,
1958                         (size < inode->i_size ? inode->i_size - size
1959                          : size - inode->i_size)
1960                 );
1961         return 0;
1962 }
1963 
1964 static inline int break_lease(struct inode *inode, unsigned int mode)
1965 {
1966         if (inode->i_flock)
1967                 return __break_lease(inode, mode, FL_LEASE);
1968         return 0;
1969 }
1970 
1971 static inline int break_deleg(struct inode *inode, unsigned int mode)
1972 {
1973         if (inode->i_flock)
1974                 return __break_lease(inode, mode, FL_DELEG);
1975         return 0;
1976 }
1977 
1978 static inline int try_break_deleg(struct inode *inode, struct inode **delegated_inode)
1979 {
1980         int ret;
1981 
1982         ret = break_deleg(inode, O_WRONLY|O_NONBLOCK);
1983         if (ret == -EWOULDBLOCK && delegated_inode) {
1984                 *delegated_inode = inode;
1985                 ihold(inode);
1986         }
1987         return ret;
1988 }
1989 
1990 static inline int break_deleg_wait(struct inode **delegated_inode)
1991 {
1992         int ret;
1993 
1994         ret = break_deleg(*delegated_inode, O_WRONLY);
1995         iput(*delegated_inode);
1996         *delegated_inode = NULL;
1997         return ret;
1998 }
1999 
2000 #else /* !CONFIG_FILE_LOCKING */
2001 static inline int locks_mandatory_locked(struct inode *inode)
2002 {
2003         return 0;
2004 }
2005 
2006 static inline int locks_mandatory_area(int rw, struct inode *inode,
2007                                        struct file *filp, loff_t offset,
2008                                        size_t count)
2009 {
2010         return 0;
2011 }
2012 
2013 static inline int __mandatory_lock(struct inode *inode)
2014 {
2015         return 0;
2016 }
2017 
2018 static inline int mandatory_lock(struct inode *inode)
2019 {
2020         return 0;
2021 }
2022 
2023 static inline int locks_verify_locked(struct inode *inode)
2024 {
2025         return 0;
2026 }
2027 
2028 static inline int locks_verify_truncate(struct inode *inode, struct file *filp,
2029                                         size_t size)
2030 {
2031         return 0;
2032 }
2033 
2034 static inline int break_lease(struct inode *inode, unsigned int mode)
2035 {
2036         return 0;
2037 }
2038 
2039 static inline int break_deleg(struct inode *inode, unsigned int mode)
2040 {
2041         return 0;
2042 }
2043 
2044 static inline int try_break_deleg(struct inode *inode, struct inode **delegated_inode)
2045 {
2046         return 0;
2047 }
2048 
2049 static inline int break_deleg_wait(struct inode **delegated_inode)
2050 {
2051         BUG();
2052         return 0;
2053 }
2054 
2055 #endif /* CONFIG_FILE_LOCKING */
2056 
2057 /* fs/open.c */
2058 struct audit_names;
2059 struct filename {
2060         const char              *name;  /* pointer to actual string */
2061         const __user char       *uptr;  /* original userland pointer */
2062         struct audit_names      *aname;
2063         bool                    separate; /* should "name" be freed? */
2064 };
2065 
2066 extern long vfs_truncate(struct path *, loff_t);
2067 extern int do_truncate(struct dentry *, loff_t start, unsigned int time_attrs,
2068                        struct file *filp);
2069 extern int do_fallocate(struct file *file, int mode, loff_t offset,
2070                         loff_t len);
2071 extern long do_sys_open(int dfd, const char __user *filename, int flags,
2072                         umode_t mode);
2073 extern struct file *file_open_name(struct filename *, int, umode_t);
2074 extern struct file *filp_open(const char *, int, umode_t);
2075 extern struct file *file_open_root(struct dentry *, struct vfsmount *,
2076                                    const char *, int);
2077 extern struct file * dentry_open(const struct path *, int, const struct cred *);
2078 extern int filp_close(struct file *, fl_owner_t id);
2079 
2080 extern struct filename *getname(const char __user *);
2081 
2082 enum {
2083         FILE_CREATED = 1,
2084         FILE_OPENED = 2
2085 };
2086 extern int finish_open(struct file *file, struct dentry *dentry,
2087                         int (*open)(struct inode *, struct file *),
2088                         int *opened);
2089 extern int finish_no_open(struct file *file, struct dentry *dentry);
2090 
2091 /* fs/ioctl.c */
2092 
2093 extern int ioctl_preallocate(struct file *filp, void __user *argp);
2094 
2095 /* fs/dcache.c */
2096 extern void __init vfs_caches_init_early(void);
2097 extern void __init vfs_caches_init(unsigned long);
2098 
2099 extern struct kmem_cache *names_cachep;
2100 
2101 extern void final_putname(struct filename *name);
2102 
2103 #define __getname()             kmem_cache_alloc(names_cachep, GFP_KERNEL)
2104 #define __putname(name)         kmem_cache_free(names_cachep, (void *)(name))
2105 #ifndef CONFIG_AUDITSYSCALL
2106 #define putname(name)           final_putname(name)
2107 #else
2108 extern void putname(struct filename *name);
2109 #endif
2110 
2111 #ifdef CONFIG_BLOCK
2112 extern int register_blkdev(unsigned int, const char *);
2113 extern void unregister_blkdev(unsigned int, const char *);
2114 extern struct block_device *bdget(dev_t);
2115 extern struct block_device *bdgrab(struct block_device *bdev);
2116 extern void bd_set_size(struct block_device *, loff_t size);
2117 extern void bd_forget(struct inode *inode);
2118 extern void bdput(struct block_device *);
2119 extern void invalidate_bdev(struct block_device *);
2120 extern void iterate_bdevs(void (*)(struct block_device *, void *), void *);
2121 extern int sync_blockdev(struct block_device *bdev);
2122 extern void kill_bdev(struct block_device *);
2123 extern struct super_block *freeze_bdev(struct block_device *);
2124 extern void emergency_thaw_all(void);
2125 extern int thaw_bdev(struct block_device *bdev, struct super_block *sb);
2126 extern int fsync_bdev(struct block_device *);
2127 extern int sb_is_blkdev_sb(struct super_block *sb);
2128 #else
2129 static inline void bd_forget(struct inode *inode) {}
2130 static inline int sync_blockdev(struct block_device *bdev) { return 0; }
2131 static inline void kill_bdev(struct block_device *bdev) {}
2132 static inline void invalidate_bdev(struct block_device *bdev) {}
2133 
2134 static inline struct super_block *freeze_bdev(struct block_device *sb)
2135 {
2136         return NULL;
2137 }
2138 
2139 static inline int thaw_bdev(struct block_device *bdev, struct super_block *sb)
2140 {
2141         return 0;
2142 }
2143 
2144 static inline void iterate_bdevs(void (*f)(struct block_device *, void *), void *arg)
2145 {
2146 }
2147 
2148 static inline int sb_is_blkdev_sb(struct super_block *sb)
2149 {
2150         return 0;
2151 }
2152 #endif
2153 extern int sync_filesystem(struct super_block *);
2154 extern const struct file_operations def_blk_fops;
2155 extern const struct file_operations def_chr_fops;
2156 extern const struct file_operations bad_sock_fops;
2157 #ifdef CONFIG_BLOCK
2158 extern int ioctl_by_bdev(struct block_device *, unsigned, unsigned long);
2159 extern int blkdev_ioctl(struct block_device *, fmode_t, unsigned, unsigned long);
2160 extern long compat_blkdev_ioctl(struct file *, unsigned, unsigned long);
2161 extern int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder);
2162 extern struct block_device *blkdev_get_by_path(const char *path, fmode_t mode,
2163                                                void *holder);
2164 extern struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode,
2165                                               void *holder);
2166 extern void blkdev_put(struct block_device *bdev, fmode_t mode);
2167 #ifdef CONFIG_SYSFS
2168 extern int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk);
2169 extern void bd_unlink_disk_holder(struct block_device *bdev,
2170                                   struct gendisk *disk);
2171 #else
2172 static inline int bd_link_disk_holder(struct block_device *bdev,
2173                                       struct gendisk *disk)
2174 {
2175         return 0;
2176 }
2177 static inline void bd_unlink_disk_holder(struct block_device *bdev,
2178                                          struct gendisk *disk)
2179 {
2180 }
2181 #endif
2182 #endif
2183 
2184 /* fs/char_dev.c */
2185 #define CHRDEV_MAJOR_HASH_SIZE  255
2186 extern int alloc_chrdev_region(dev_t *, unsigned, unsigned, const char *);
2187 extern int register_chrdev_region(dev_t, unsigned, const char *);
2188 extern int __register_chrdev(unsigned int major, unsigned int baseminor,
2189                              unsigned int count, const char *name,
2190                              const struct file_operations *fops);
2191 extern void __unregister_chrdev(unsigned int major, unsigned int baseminor,
2192                                 unsigned int count, const char *name);
2193 extern void unregister_chrdev_region(dev_t, unsigned);
2194 extern void chrdev_show(struct seq_file *,off_t);
2195 
2196 static inline int register_chrdev(unsigned int major, const char *name,
2197                                   const struct file_operations *fops)
2198 {
2199         return __register_chrdev(major, 0, 256, name, fops);
2200 }
2201 
2202 static inline void unregister_chrdev(unsigned int major, const char *name)
2203 {
2204         __unregister_chrdev(major, 0, 256, name);
2205 }
2206 
2207 /* fs/block_dev.c */
2208 #define BDEVNAME_SIZE   32      /* Largest string for a blockdev identifier */
2209 #define BDEVT_SIZE      10      /* Largest string for MAJ:MIN for blkdev */
2210 
2211 #ifdef CONFIG_BLOCK
2212 #define BLKDEV_MAJOR_HASH_SIZE  255
2213 extern const char *__bdevname(dev_t, char *buffer);
2214 extern const char *bdevname(struct block_device *bdev, char *buffer);
2215 extern struct block_device *lookup_bdev(const char *);
2216 extern void blkdev_show(struct seq_file *,off_t);
2217 
2218 #else
2219 #define BLKDEV_MAJOR_HASH_SIZE  0
2220 #endif
2221 
2222 extern void init_special_inode(struct inode *, umode_t, dev_t);
2223 
2224 /* Invalid inode operations -- fs/bad_inode.c */
2225 extern void make_bad_inode(struct inode *);
2226 extern int is_bad_inode(struct inode *);
2227 
2228 #ifdef CONFIG_BLOCK
2229 /*
2230  * return READ, READA, or WRITE
2231  */
2232 #define bio_rw(bio)             ((bio)->bi_rw & (RW_MASK | RWA_MASK))
2233 
2234 /*
2235  * return data direction, READ or WRITE
2236  */
2237 #define bio_data_dir(bio)       ((bio)->bi_rw & 1)
2238 
2239 extern void check_disk_size_change(struct gendisk *disk,
2240                                    struct block_device *bdev);
2241 extern int revalidate_disk(struct gendisk *);
2242 extern int check_disk_change(struct block_device *);
2243 extern int __invalidate_device(struct block_device *, bool);
2244 extern int invalidate_partition(struct gendisk *, int);
2245 #endif
2246 unsigned long invalidate_mapping_pages(struct address_space *mapping,
2247                                         pgoff_t start, pgoff_t end);
2248 
2249 static inline void invalidate_remote_inode(struct inode *inode)
2250 {
2251         if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2252             S_ISLNK(inode->i_mode))
2253                 invalidate_mapping_pages(inode->i_mapping, 0, -1);
2254 }
2255 extern int invalidate_inode_pages2(struct address_space *mapping);
2256 extern int invalidate_inode_pages2_range(struct address_space *mapping,
2257                                          pgoff_t start, pgoff_t end);
2258 extern int write_inode_now(struct inode *, int);
2259 extern int filemap_fdatawrite(struct address_space *);
2260 extern int filemap_flush(struct address_space *);
2261 extern int filemap_fdatawait(struct address_space *);
2262 extern int filemap_fdatawait_range(struct address_space *, loff_t lstart,
2263                                    loff_t lend);
2264 extern int filemap_write_and_wait(struct address_space *mapping);
2265 extern int filemap_write_and_wait_range(struct address_space *mapping,
2266                                         loff_t lstart, loff_t lend);
2267 extern int __filemap_fdatawrite_range(struct address_space *mapping,
2268                                 loff_t start, loff_t end, int sync_mode);
2269 extern int filemap_fdatawrite_range(struct address_space *mapping,
2270                                 loff_t start, loff_t end);
2271 
2272 extern int vfs_fsync_range(struct file *file, loff_t start, loff_t end,
2273                            int datasync);
2274 extern int vfs_fsync(struct file *file, int datasync);
2275 extern int generic_write_sync(struct file *file, loff_t pos, loff_t count);
2276 extern void emergency_sync(void);
2277 extern void emergency_remount(void);
2278 #ifdef CONFIG_BLOCK
2279 extern sector_t bmap(struct inode *, sector_t);
2280 #endif
2281 extern int notify_change(struct dentry *, struct iattr *, struct inode **);
2282 extern int inode_permission(struct inode *, int);
2283 extern int generic_permission(struct inode *, int);
2284 
2285 static inline bool execute_ok(struct inode *inode)
2286 {
2287         return (inode->i_mode & S_IXUGO) || S_ISDIR(inode->i_mode);
2288 }
2289 
2290 static inline struct inode *file_inode(struct file *f)
2291 {
2292         return f->f_inode;
2293 }
2294 
2295 static inline void file_start_write(struct file *file)
2296 {
2297         if (!S_ISREG(file_inode(file)->i_mode))
2298                 return;
2299         __sb_start_write(file_inode(file)->i_sb, SB_FREEZE_WRITE, true);
2300 }
2301 
2302 static inline bool file_start_write_trylock(struct file *file)
2303 {
2304         if (!S_ISREG(file_inode(file)->i_mode))
2305                 return true;
2306         return __sb_start_write(file_inode(file)->i_sb, SB_FREEZE_WRITE, false);
2307 }
2308 
2309 static inline void file_end_write(struct file *file)
2310 {
2311         if (!S_ISREG(file_inode(file)->i_mode))
2312                 return;
2313         __sb_end_write(file_inode(file)->i_sb, SB_FREEZE_WRITE);
2314 }
2315 
2316 /*
2317  * get_write_access() gets write permission for a file.
2318  * put_write_access() releases this write permission.
2319  * This is used for regular files.
2320  * We cannot support write (and maybe mmap read-write shared) accesses and
2321  * MAP_DENYWRITE mmappings simultaneously. The i_writecount field of an inode
2322  * can have the following values:
2323  * 0: no writers, no VM_DENYWRITE mappings
2324  * < 0: (-i_writecount) vm_area_structs with VM_DENYWRITE set exist
2325  * > 0: (i_writecount) users are writing to the file.
2326  *
2327  * Normally we operate on that counter with atomic_{inc,dec} and it's safe
2328  * except for the cases where we don't hold i_writecount yet. Then we need to
2329  * use {get,deny}_write_access() - these functions check the sign and refuse
2330  * to do the change if sign is wrong.
2331  */
2332 static inline int get_write_access(struct inode *inode)
2333 {
2334         return atomic_inc_unless_negative(&inode->i_writecount) ? 0 : -ETXTBSY;
2335 }
2336 static inline int deny_write_access(struct file *file)
2337 {
2338         struct inode *inode = file_inode(file);
2339         return atomic_dec_unless_positive(&inode->i_writecount) ? 0 : -ETXTBSY;
2340 }
2341 static inline void put_write_access(struct inode * inode)
2342 {
2343         atomic_dec(&inode->i_writecount);
2344 }
2345 static inline void allow_write_access(struct file *file)
2346 {
2347         if (file)
2348                 atomic_inc(&file_inode(file)->i_writecount);
2349 }
2350 static inline bool inode_is_open_for_write(const struct inode *inode)
2351 {
2352         return atomic_read(&inode->i_writecount) > 0;
2353 }
2354 
2355 #ifdef CONFIG_IMA
2356 static inline void i_readcount_dec(struct inode *inode)
2357 {
2358         BUG_ON(!atomic_read(&inode->i_readcount));
2359         atomic_dec(&inode->i_readcount);
2360 }
2361 static inline void i_readcount_inc(struct inode *inode)
2362 {
2363         atomic_inc(&inode->i_readcount);
2364 }
2365 #else
2366 static inline void i_readcount_dec(struct inode *inode)
2367 {
2368         return;
2369 }
2370 static inline void i_readcount_inc(struct inode *inode)
2371 {
2372         return;
2373 }
2374 #endif
2375 extern int do_pipe_flags(int *, int);
2376 
2377 extern int kernel_read(struct file *, loff_t, char *, unsigned long);
2378 extern ssize_t kernel_write(struct file *, const char *, size_t, loff_t);
2379 extern struct file * open_exec(const char *);
2380  
2381 /* fs/dcache.c -- generic fs support functions */
2382 extern int is_subdir(struct dentry *, struct dentry *);
2383 extern int path_is_under(struct path *, struct path *);
2384 
2385 #include <linux/err.h>
2386 
2387 /* needed for stackable file system support */
2388 extern loff_t default_llseek(struct file *file, loff_t offset, int whence);
2389 
2390 extern loff_t vfs_llseek(struct file *file, loff_t offset, int whence);
2391 
2392 extern int inode_init_always(struct super_block *, struct inode *);
2393 extern void inode_init_once(struct inode *);
2394 extern void address_space_init_once(struct address_space *mapping);
2395 extern struct inode * igrab(struct inode *);
2396 extern ino_t iunique(struct super_block *, ino_t);
2397 extern int inode_needs_sync(struct inode *inode);
2398 extern int generic_delete_inode(struct inode *inode);
2399 static inline int generic_drop_inode(struct inode *inode)
2400 {
2401         return !inode->i_nlink || inode_unhashed(inode);
2402 }
2403 
2404 extern struct inode *ilookup5_nowait(struct super_block *sb,
2405                 unsigned long hashval, int (*test)(struct inode *, void *),
2406                 void *data);
2407 extern struct inode *ilookup5(struct super_block *sb, unsigned long hashval,
2408                 int (*test)(struct inode *, void *), void *data);
2409 extern struct inode *ilookup(struct super_block *sb, unsigned long ino);
2410 
2411 extern struct inode * iget5_locked(struct super_block *, unsigned long, int (*test)(struct inode *, void *), int (*set)(struct inode *, void *), void *);
2412 extern struct inode * iget_locked(struct super_block *, unsigned long);
2413 extern int insert_inode_locked4(struct inode *, unsigned long, int (*test)(struct inode *, void *), void *);
2414 extern int insert_inode_locked(struct inode *);
2415 #ifdef CONFIG_DEBUG_LOCK_ALLOC
2416 extern void lockdep_annotate_inode_mutex_key(struct inode *inode);
2417 #else
2418 static inline void lockdep_annotate_inode_mutex_key(struct inode *inode) { };
2419 #endif
2420 extern void unlock_new_inode(struct inode *);
2421 extern unsigned int get_next_ino(void);
2422 
2423 extern void __iget(struct inode * inode);
2424 extern void iget_failed(struct inode *);
2425 extern void clear_inode(struct inode *);
2426 extern void __destroy_inode(struct inode *);
2427 extern struct inode *new_inode_pseudo(struct super_block *sb);
2428 extern struct inode *new_inode(struct super_block *sb);
2429 extern void free_inode_nonrcu(struct inode *inode);
2430 extern int should_remove_suid(struct dentry *);
2431 extern int file_remove_suid(struct file *);
2432 
2433 extern void __insert_inode_hash(struct inode *, unsigned long hashval);
2434 static inline void insert_inode_hash(struct inode *inode)
2435 {
2436         __insert_inode_hash(inode, inode->i_ino);
2437 }
2438 
2439 extern void __remove_inode_hash(struct inode *);
2440 static inline void remove_inode_hash(struct inode *inode)
2441 {
2442         if (!inode_unhashed(inode))
2443                 __remove_inode_hash(inode);
2444 }
2445 
2446 extern void inode_sb_list_add(struct inode *inode);
2447 
2448 #ifdef CONFIG_BLOCK
2449 extern void submit_bio(int, struct bio *);
2450 extern int bdev_read_only(struct block_device *);
2451 #endif
2452 extern int set_blocksize(struct block_device *, int);
2453 extern int sb_set_blocksize(struct super_block *, int);
2454 extern int sb_min_blocksize(struct super_block *, int);
2455 
2456 extern int generic_file_mmap(struct file *, struct vm_area_struct *);
2457 extern int generic_file_readonly_mmap(struct file *, struct vm_area_struct *);
2458 extern int generic_file_remap_pages(struct vm_area_struct *, unsigned long addr,
2459                 unsigned long size, pgoff_t pgoff);
2460 extern int file_read_actor(read_descriptor_t * desc, struct page *page, unsigned long offset, unsigned long size);
2461 int generic_write_checks(struct file *file, loff_t *pos, size_t *count, int isblk);
2462 extern ssize_t generic_file_aio_read(struct kiocb *, const struct iovec *, unsigned long, loff_t);
2463 extern ssize_t __generic_file_aio_write(struct kiocb *, const struct iovec *, unsigned long,
2464                 loff_t *);
2465 extern ssize_t generic_file_aio_write(struct kiocb *, const struct iovec *, unsigned long, loff_t);
2466 extern ssize_t generic_file_direct_write(struct kiocb *, const struct iovec *,
2467                 unsigned long *, loff_t, loff_t *, size_t, size_t);
2468 extern ssize_t generic_file_buffered_write(struct kiocb *, const struct iovec *,
2469                 unsigned long, loff_t, loff_t *, size_t, ssize_t);
2470 extern ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos);
2471 extern ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos);
2472 extern int generic_segment_checks(const struct iovec *iov,
2473                 unsigned long *nr_segs, size_t *count, int access_flags);
2474 
2475 /* fs/block_dev.c */
2476 extern ssize_t blkdev_aio_write(struct kiocb *iocb, const struct iovec *iov,
2477                                 unsigned long nr_segs, loff_t pos);
2478 extern int blkdev_fsync(struct file *filp, loff_t start, loff_t end,
2479                         int datasync);
2480 extern void block_sync_page(struct page *page);
2481 
2482 /* fs/splice.c */
2483 extern ssize_t generic_file_splice_read(struct file *, loff_t *,
2484                 struct pipe_inode_info *, size_t, unsigned int);
2485 extern ssize_t default_file_splice_read(struct file *, loff_t *,
2486                 struct pipe_inode_info *, size_t, unsigned int);
2487 extern ssize_t generic_file_splice_write(struct pipe_inode_info *,
2488                 struct file *, loff_t *, size_t, unsigned int);
2489 extern ssize_t generic_splice_sendpage(struct pipe_inode_info *pipe,
2490                 struct file *out, loff_t *, size_t len, unsigned int flags);
2491 
2492 extern void
2493 file_ra_state_init(struct file_ra_state *ra, struct address_space *mapping);
2494 extern loff_t noop_llseek(struct file *file, loff_t offset, int whence);
2495 extern loff_t no_llseek(struct file *file, loff_t offset, int whence);
2496 extern loff_t vfs_setpos(struct file *file, loff_t offset, loff_t maxsize);
2497 extern loff_t generic_file_llseek(struct file *file, loff_t offset, int whence);
2498 extern loff_t generic_file_llseek_size(struct file *file, loff_t offset,
2499                 int whence, loff_t maxsize, loff_t eof);
2500 extern loff_t fixed_size_llseek(struct file *file, loff_t offset,
2501                 int whence, loff_t size);
2502 extern int generic_file_open(struct inode * inode, struct file * filp);
2503 extern int nonseekable_open(struct inode * inode, struct file * filp);
2504 
2505 #ifdef CONFIG_FS_XIP
2506 extern ssize_t xip_file_read(struct file *filp, char __user *buf, size_t len,
2507                              loff_t *ppos);
2508 extern int xip_file_mmap(struct file * file, struct vm_area_struct * vma);
2509 extern ssize_t xip_file_write(struct file *filp, const char __user *buf,
2510                               size_t len, loff_t *ppos);
2511 extern int xip_truncate_page(struct address_space *mapping, loff_t from);
2512 #else
2513 static inline int xip_truncate_page(struct address_space *mapping, loff_t from)
2514 {
2515         return 0;
2516 }
2517 #endif
2518 
2519 #ifdef CONFIG_BLOCK
2520 typedef void (dio_submit_t)(int rw, struct bio *bio, struct inode *inode,
2521                             loff_t file_offset);
2522 
2523 enum {
2524         /* need locking between buffered and direct access */
2525         DIO_LOCKING     = 0x01,
2526 
2527         /* filesystem does not support filling holes */
2528         DIO_SKIP_HOLES  = 0x02,
2529 };
2530 
2531 void dio_end_io(struct bio *bio, int error);
2532 
2533 ssize_t __blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode,
2534         struct block_device *bdev, const struct iovec *iov, loff_t offset,
2535         unsigned long nr_segs, get_block_t get_block, dio_iodone_t end_io,
2536         dio_submit_t submit_io, int flags);
2537 
2538 static inline ssize_t blockdev_direct_IO(int rw, struct kiocb *iocb,
2539                 struct inode *inode, const struct iovec *iov, loff_t offset,
2540                 unsigned long nr_segs, get_block_t get_block)
2541 {
2542         return __blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
2543                                     offset, nr_segs, get_block, NULL, NULL,
2544                                     DIO_LOCKING | DIO_SKIP_HOLES);
2545 }
2546 #endif
2547 
2548 void inode_dio_wait(struct inode *inode);
2549 void inode_dio_done(struct inode *inode);
2550 
2551 extern const struct file_operations generic_ro_fops;
2552 
2553 #define special_file(m) (S_ISCHR(m)||S_ISBLK(m)||S_ISFIFO(m)||S_ISSOCK(m))
2554 
2555 extern int vfs_readlink(struct dentry *, char __user *, int, const char *);
2556 extern int page_readlink(struct dentry *, char __user *, int);
2557 extern void *page_follow_link_light(struct dentry *, struct nameidata *);
2558 extern void page_put_link(struct dentry *, struct nameidata *, void *);
2559 extern int __page_symlink(struct inode *inode, const char *symname, int len,
2560                 int nofs);
2561 extern int page_symlink(struct inode *inode, const char *symname, int len);
2562 extern const struct inode_operations page_symlink_inode_operations;
2563 extern void kfree_put_link(struct dentry *, struct nameidata *, void *);
2564 extern int generic_readlink(struct dentry *, char __user *, int);
2565 extern void generic_fillattr(struct inode *, struct kstat *);
2566 int vfs_getattr_nosec(struct path *path, struct kstat *stat);
2567 extern int vfs_getattr(struct path *, struct kstat *);
2568 void __inode_add_bytes(struct inode *inode, loff_t bytes);
2569 void inode_add_bytes(struct inode *inode, loff_t bytes);
2570 void __inode_sub_bytes(struct inode *inode, loff_t bytes);
2571 void inode_sub_bytes(struct inode *inode, loff_t bytes);
2572 loff_t inode_get_bytes(struct inode *inode);
2573 void inode_set_bytes(struct inode *inode, loff_t bytes);
2574 
2575 extern int vfs_readdir(struct file *, filldir_t, void *);
2576 extern int iterate_dir(struct file *, struct dir_context *);
2577 
2578 extern int vfs_stat(const char __user *, struct kstat *);
2579 extern int vfs_lstat(const char __user *, struct kstat *);
2580 extern int vfs_fstat(unsigned int, struct kstat *);
2581 extern int vfs_fstatat(int , const char __user *, struct kstat *, int);
2582 
2583 extern int do_vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd,
2584                     unsigned long arg);
2585 extern int __generic_block_fiemap(struct inode *inode,
2586                                   struct fiemap_extent_info *fieinfo,
2587                                   loff_t start, loff_t len,
2588                                   get_block_t *get_block);
2589 extern int generic_block_fiemap(struct inode *inode,
2590                                 struct fiemap_extent_info *fieinfo, u64 start,
2591                                 u64 len, get_block_t *get_block);
2592 
2593 extern void get_filesystem(struct file_system_type *fs);
2594 extern void put_filesystem(struct file_system_type *fs);
2595 extern struct file_system_type *get_fs_type(const char *name);
2596 extern struct super_block *get_super(struct block_device *);
2597 extern struct super_block *get_super_thawed(struct block_device *);
2598 extern struct super_block *get_active_super(struct block_device *bdev);
2599 extern void drop_super(struct super_block *sb);
2600 extern void iterate_supers(void (*)(struct super_block *, void *), void *);
2601 extern void iterate_supers_type(struct file_system_type *,
2602                                 void (*)(struct super_block *, void *), void *);
2603 
2604 extern int dcache_dir_open(struct inode *, struct file *);
2605 extern int dcache_dir_close(struct inode *, struct file *);
2606 extern loff_t dcache_dir_lseek(struct file *, loff_t, int);
2607 extern int dcache_readdir(struct file *, struct dir_context *);
2608 extern int simple_setattr(struct dentry *, struct iattr *);
2609 extern int simple_getattr(struct vfsmount *, struct dentry *, struct kstat *);
2610 extern int simple_statfs(struct dentry *, struct kstatfs *);
2611 extern int simple_open(struct inode *inode, struct file *file);
2612 extern int simple_link(struct dentry *, struct inode *, struct dentry *);
2613 extern int simple_unlink(struct inode *, struct dentry *);
2614 extern int simple_rmdir(struct inode *, struct dentry *);
2615 extern int simple_rename(struct inode *, struct dentry *, struct inode *, struct dentry *);
2616 extern int noop_fsync(struct file *, loff_t, loff_t, int);
2617 extern int simple_empty(struct dentry *);
2618 extern int simple_readpage(struct file *file, struct page *page);
2619 extern int simple_write_begin(struct file *file, struct address_space *mapping,
2620                         loff_t pos, unsigned len, unsigned flags,
2621                         struct page **pagep, void **fsdata);
2622 extern int simple_write_end(struct file *file, struct address_space *mapping,
2623                         loff_t pos, unsigned len, unsigned copied,
2624                         struct page *page, void *fsdata);
2625 extern int always_delete_dentry(const struct dentry *);
2626 extern struct inode *alloc_anon_inode(struct super_block *);
2627 extern const struct dentry_operations simple_dentry_operations;
2628 
2629 extern struct dentry *simple_lookup(struct inode *, struct dentry *, unsigned int flags);
2630 extern ssize_t generic_read_dir(struct file *, char __user *, size_t, loff_t *);
2631 extern const struct file_operations simple_dir_operations;
2632 extern const struct inode_operations simple_dir_inode_operations;
2633 struct tree_descr { char *name; const struct file_operations *ops; int mode; };
2634 struct dentry *d_alloc_name(struct dentry *, const char *);
2635 extern int simple_fill_super(struct super_block *, unsigned long, struct tree_descr *);
2636 extern int simple_pin_fs(struct file_system_type *, struct vfsmount **mount, int *count);
2637 extern void simple_release_fs(struct vfsmount **mount, int *count);
2638 
2639 extern ssize_t simple_read_from_buffer(void __user *to, size_t count,
2640                         loff_t *ppos, const void *from, size_t available);
2641 extern ssize_t simple_write_to_buffer(void *to, size_t available, loff_t *ppos,
2642                 const void __user *from, size_t count);
2643 
2644 extern int generic_file_fsync(struct file *, loff_t, loff_t, int);
2645 
2646 extern int generic_check_addressable(unsigned, u64);
2647 
2648 #ifdef CONFIG_MIGRATION
2649 extern int buffer_migrate_page(struct address_space *,
2650                                 struct page *, struct page *,
2651                                 enum migrate_mode);
2652 #else
2653 #define buffer_migrate_page NULL
2654 #endif
2655 
2656 extern int inode_change_ok(const struct inode *, struct iattr *);
2657 extern int inode_newsize_ok(const struct inode *, loff_t offset);
2658 extern void setattr_copy(struct inode *inode, const struct iattr *attr);
2659 
2660 extern int file_update_time(struct file *file);
2661 
2662 extern int generic_show_options(struct seq_file *m, struct dentry *root);
2663 extern void save_mount_options(struct super_block *sb, char *options);
2664 extern void replace_mount_options(struct super_block *sb, char *options);
2665 
2666 static inline ino_t parent_ino(struct dentry *dentry)
2667 {
2668         ino_t res;
2669 
2670         /*
2671          * Don't strictly need d_lock here? If the parent ino could change
2672          * then surely we'd have a deeper race in the caller?
2673          */
2674         spin_lock(&dentry->d_lock);
2675         res = dentry->d_parent->d_inode->i_ino;
2676         spin_unlock(&dentry->d_lock);
2677         return res;
2678 }
2679 
2680 /* Transaction based IO helpers */
2681 
2682 /*
2683  * An argresp is stored in an allocated page and holds the
2684  * size of the argument or response, along with its content
2685  */
2686 struct simple_transaction_argresp {
2687         ssize_t size;
2688         char data[0];
2689 };
2690 
2691 #define SIMPLE_TRANSACTION_LIMIT (PAGE_SIZE - sizeof(struct simple_transaction_argresp))
2692 
2693 char *simple_transaction_get(struct file *file, const char __user *buf,
2694                                 size_t size);
2695 ssize_t simple_transaction_read(struct file *file, char __user *buf,
2696                                 size_t size, loff_t *pos);
2697 int simple_transaction_release(struct inode *inode, struct file *file);
2698 
2699 void simple_transaction_set(struct file *file, size_t n);
2700 
2701 /*
2702  * simple attribute files
2703  *
2704  * These attributes behave similar to those in sysfs:
2705  *
2706  * Writing to an attribute immediately sets a value, an open file can be
2707  * written to multiple times.
2708  *
2709  * Reading from an attribute creates a buffer from the value that might get
2710  * read with multiple read calls. When the attribute has been read
2711  * completely, no further read calls are possible until the file is opened
2712  * again.
2713  *
2714  * All attributes contain a text representation of a numeric value
2715  * that are accessed with the get() and set() functions.
2716  */
2717 #define DEFINE_SIMPLE_ATTRIBUTE(__fops, __get, __set, __fmt)            \
2718 static int __fops ## _open(struct inode *inode, struct file *file)      \
2719 {                                                                       \
2720         __simple_attr_check_format(__fmt, 0ull);                        \
2721         return simple_attr_open(inode, file, __get, __set, __fmt);      \
2722 }                                                                       \
2723 static const struct file_operations __fops = {                          \
2724         .owner   = THIS_MODULE,                                         \
2725         .open    = __fops ## _open,                                     \
2726         .release = simple_attr_release,                                 \
2727         .read    = simple_attr_read,                                    \
2728         .write   = simple_attr_write,                                   \
2729         .llseek  = generic_file_llseek,                                 \
2730 };
2731 
2732 static inline __printf(1, 2)
2733 void __simple_attr_check_format(const char *fmt, ...)
2734 {
2735         /* don't do anything, just let the compiler check the arguments; */
2736 }
2737 
2738 int simple_attr_open(struct inode *inode, struct file *file,
2739                      int (*get)(void *, u64 *), int (*set)(void *, u64),
2740                      const char *fmt);
2741 int simple_attr_release(struct inode *inode, struct file *file);
2742 ssize_t simple_attr_read(struct file *file, char __user *buf,
2743                          size_t len, loff_t *ppos);
2744 ssize_t simple_attr_write(struct file *file, const char __user *buf,
2745                           size_t len, loff_t *ppos);
2746 
2747 struct ctl_table;
2748 int proc_nr_files(struct ctl_table *table, int write,
2749                   void __user *buffer, size_t *lenp, loff_t *ppos);
2750 int proc_nr_dentry(struct ctl_table *table, int write,
2751                   void __user *buffer, size_t *lenp, loff_t *ppos);
2752 int proc_nr_inodes(struct ctl_table *table, int write,
2753                    void __user *buffer, size_t *lenp, loff_t *ppos);
2754 int __init get_filesystem_list(char *buf);
2755 
2756 #define __FMODE_EXEC            ((__force int) FMODE_EXEC)
2757 #define __FMODE_NONOTIFY        ((__force int) FMODE_NONOTIFY)
2758 
2759 #define ACC_MODE(x) ("\004\002\006\006"[(x)&O_ACCMODE])
2760 #define OPEN_FMODE(flag) ((__force fmode_t)(((flag + 1) & O_ACCMODE) | \
2761                                             (flag & __FMODE_NONOTIFY)))
2762 
2763 static inline int is_sxid(umode_t mode)
2764 {
2765         return (mode & S_ISUID) || ((mode & S_ISGID) && (mode & S_IXGRP));
2766 }
2767 
2768 static inline void inode_has_no_xattr(struct inode *inode)
2769 {
2770         if (!is_sxid(inode->i_mode) && (inode->i_sb->s_flags & MS_NOSEC))
2771                 inode->i_flags |= S_NOSEC;
2772 }
2773 
2774 static inline bool dir_emit(struct dir_context *ctx,
2775                             const char *name, int namelen,
2776                             u64 ino, unsigned type)
2777 {
2778         return ctx->actor(ctx, name, namelen, ctx->pos, ino, type) == 0;
2779 }
2780 static inline bool dir_emit_dot(struct file *file, struct dir_context *ctx)
2781 {
2782         return ctx->actor(ctx, ".", 1, ctx->pos,
2783                           file->f_path.dentry->d_inode->i_ino, DT_DIR) == 0;
2784 }
2785 static inline bool dir_emit_dotdot(struct file *file, struct dir_context *ctx)
2786 {
2787         return ctx->actor(ctx, "..", 2, ctx->pos,
2788                           parent_ino(file->f_path.dentry), DT_DIR) == 0;
2789 }
2790 static inline bool dir_emit_dots(struct file *file, struct dir_context *ctx)
2791 {
2792         if (ctx->pos == 0) {
2793                 if (!dir_emit_dot(file, ctx))
2794                         return false;
2795                 ctx->pos = 1;
2796         }
2797         if (ctx->pos == 1) {
2798                 if (!dir_emit_dotdot(file, ctx))
2799                         return false;
2800                 ctx->pos = 2;
2801         }
2802         return true;
2803 }
2804 static inline bool dir_relax(struct inode *inode)
2805 {
2806         mutex_unlock(&inode->i_mutex);
2807         mutex_lock(&inode->i_mutex);
2808         return !IS_DEADDIR(inode);
2809 }
2810 
2811 #endif /* _LINUX_FS_H */
2812 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp