fs/fuse/fuse_i.h

   1 /*
   2   FUSE: Filesystem in Userspace
   3   Copyright (C) 2001-2008  Miklos Szeredi <miklos@szeredi.hu>
   4
   5   This program can be distributed under the terms of the GNU GPL.
   6   See the file COPYING.
   7 */
   8
   9 #ifndef _FS_FUSE_I_H
  10 #define _FS_FUSE_I_H
  11
  12 #include <linux/fuse.h>
  13 #include <linux/fs.h>
  14 #include <linux/mount.h>
  15 #include <linux/wait.h>
  16 #include <linux/list.h>
  17 #include <linux/spinlock.h>
  18 #include <linux/mm.h>
  19 #include <linux/backing-dev.h>
  20 #include <linux/mutex.h>
  21 #include <linux/rwsem.h>
  22 #include <linux/rbtree.h>
  23 #include <linux/poll.h>
  24 #include <linux/workqueue.h>
  25
  26 /** Max number of pages that can be used in a single read request */
  27 #define FUSE_MAX_PAGES_PER_REQ 32
  28
  29 /** Bias for fi->writectr, meaning new writepages must not be sent */
  30 #define FUSE_NOWRITE INT_MIN
  31
  32 /** It could be as large as PATH_MAX, but would that have any uses? */
  33 #define FUSE_NAME_MAX 1024
  34
  35 /** Number of dentries for each connection in the control filesystem */
  36 #define FUSE_CTL_NUM_DENTRIES 5
  37
  38 /** If the FUSE_DEFAULT_PERMISSIONS flag is given, the filesystem
  39     module will check permissions based on the file mode.  Otherwise no
  40     permission checking is done in the kernel */
  41 #define FUSE_DEFAULT_PERMISSIONS (1 << 0)
  42
  43 /** If the FUSE_ALLOW_OTHER flag is given, then not only the user
  44     doing the mount will be allowed to access the filesystem */
  45 #define FUSE_ALLOW_OTHER         (1 << 1)
  46
  47 /** Number of page pointers embedded in fuse_req */
  48 #define FUSE_REQ_INLINE_PAGES 1
  49
  50 /** List of active connections */
  51 extern struct list_head fuse_conn_list;
  52
  53 /** Global mutex protecting fuse_conn_list and the control filesystem */
  54 extern struct mutex fuse_mutex;
  55
  56 /** Module parameters */
  57 extern unsigned max_user_bgreq;
  58 extern unsigned max_user_congthresh;
  59
  60 /* One forget request */
  61 struct fuse_forget_link {
  62         struct fuse_forget_one forget_one;
  63         struct fuse_forget_link *next;
  64 };
  65
  66 /** FUSE inode */
  67 struct fuse_inode {
  68         /** Inode data */
  69         struct inode inode;
  70
  71         /** Unique ID, which identifies the inode between userspace
  72          * and kernel */
  73         u64 nodeid;
  74
  75         /** Number of lookups on this inode */
  76         u64 nlookup;
  77
  78         /** The request used for sending the FORGET message */
  79         struct fuse_forget_link *forget;
  80
  81         /** Time in jiffies until the file attributes are valid */
  82         u64 i_time;
  83
  84         /** The sticky bit in inode->i_mode may have been removed, so
  85             preserve the original mode */
  86         umode_t orig_i_mode;
  87
  88         /** 64 bit inode number */
  89         u64 orig_ino;
  90
  91         /** Version of last attribute change */
  92         u64 attr_version;
  93
  94         /** Files usable in writepage.  Protected by fc->lock */
  95         struct list_head write_files;
  96
  97         /** Writepages pending on truncate or fsync */
  98         struct list_head queued_writes;
  99
 100         /** Number of sent writes, a negative bias (FUSE_NOWRITE)
 101          * means more writes are blocked */
 102         int writectr;
 103
 104         /** Waitq for writepage completion */
 105         wait_queue_head_t page_waitq;
 106
 107         /** List of writepage requestst (pending or sent) */
 108         struct list_head writepages;
 109
 110         /** Miscellaneous bits describing inode state */
 111         unsigned long state;
 112 };
 113
 114 /** FUSE inode state bits */
 115 enum {
 116         /** Advise readdirplus  */
 117         FUSE_I_ADVISE_RDPLUS,
 118         /** Initialized with readdirplus */
 119         FUSE_I_INIT_RDPLUS,
 120         /** An operation changing file size is in progress  */
 121         FUSE_I_SIZE_UNSTABLE,
 122 };
 123
 124 struct fuse_conn;
 125
 126 /** FUSE specific file data */
 127 struct fuse_file {
 128         /** Fuse connection for this file */
 129         struct fuse_conn *fc;
 130
 131         /** Request reserved for flush and release */
 132         struct fuse_req *reserved_req;
 133
 134         /** Kernel file handle guaranteed to be unique */
 135         u64 kh;
 136
 137         /** File handle used by userspace */
 138         u64 fh;
 139
 140         /** Node id of this file */
 141         u64 nodeid;
 142
 143         /** Refcount */
 144         atomic_t count;
 145
 146         /** FOPEN_* flags returned by open */
 147         u32 open_flags;
 148
 149         /** Entry on inode's write_files list */
 150         struct list_head write_entry;
 151
 152         /** RB node to be linked on fuse_conn->polled_files */
 153         struct rb_node polled_node;
 154
 155         /** Wait queue head for poll */
 156         wait_queue_head_t poll_wait;
 157
 158         /** Has flock been performed on this file? */
 159         bool flock:1;
 160 };
 161
 162 /** One input argument of a request */
 163 struct fuse_in_arg {
 164         unsigned size;
 165         const void *value;
 166 };
 167
 168 /** The request input */
 169 struct fuse_in {
 170         /** The request header */
 171         struct fuse_in_header h;
 172
 173         /** True if the data for the last argument is in req->pages */
 174         unsigned argpages:1;
 175
 176         /** Number of arguments */
 177         unsigned numargs;
 178
 179         /** Array of arguments */
 180         struct fuse_in_arg args[3];
 181 };
 182
 183 /** One output argument of a request */
 184 struct fuse_arg {
 185         unsigned size;
 186         void *value;
 187 };
 188
 189 /** The request output */
 190 struct fuse_out {
 191         /** Header returned from userspace */
 192         struct fuse_out_header h;
 193
 194         /*
 195          * The following bitfields are not changed during the request
 196          * processing
 197          */
 198
 199         /** Last argument is variable length (can be shorter than
 200             arg->size) */
 201         unsigned argvar:1;
 202
 203         /** Last argument is a list of pages to copy data to */
 204         unsigned argpages:1;
 205
 206         /** Zero partially or not copied pages */
 207         unsigned page_zeroing:1;
 208
 209         /** Pages may be replaced with new ones */
 210         unsigned page_replace:1;
 211
 212         /** Number or arguments */
 213         unsigned numargs;
 214
 215         /** Array of arguments */
 216         struct fuse_arg args[2];
 217 };
 218
 219 /** FUSE page descriptor */
 220 struct fuse_page_desc {
 221         unsigned int length;
 222         unsigned int offset;
 223 };
 224
 225 struct fuse_args {
 226         struct {
 227                 struct {
 228                         uint32_t opcode;
 229                         uint64_t nodeid;
 230                 } h;
 231                 unsigned numargs;
 232                 struct fuse_in_arg args[3];
 233
 234         } in;
 235         struct {
 236                 unsigned argvar:1;
 237                 unsigned numargs;
 238                 struct fuse_arg args[2];
 239         } out;
 240 };
 241
 242 #define FUSE_ARGS(args) struct fuse_args args = {}
 243
 244 /** The request IO state (for asynchronous processing) */
 245 struct fuse_io_priv {
 246         int async;
 247         spinlock_t lock;
 248         unsigned reqs;
 249         ssize_t bytes;
 250         size_t size;
 251         __u64 offset;
 252         bool write;
 253         int err;
 254         struct kiocb *iocb;
 255         struct file *file;
 256         struct completion *done;
 257 };
 258
 259 /**
 260  * Request flags
 261  *
 262  * FR_ISREPLY:          set if the request has reply
 263  * FR_FORCE:            force sending of the request even if interrupted
 264  * FR_BACKGROUND:       request is sent in the background
 265  * FR_WAITING:          request is counted as "waiting"
 266  * FR_ABORTED:          the request was aborted
 267  * FR_INTERRUPTED:      the request has been interrupted
 268  * FR_LOCKED:           data is being copied to/from the request
 269  * FR_PENDING:          request is not yet in userspace
 270  * FR_SENT:             request is in userspace, waiting for an answer
 271  * FR_FINISHED:         request is finished
 272  * FR_PRIVATE:          request is on private list
 273  */
 274 enum fuse_req_flag {
 275         FR_ISREPLY,
 276         FR_FORCE,
 277         FR_BACKGROUND,
 278         FR_WAITING,
 279         FR_ABORTED,
 280         FR_INTERRUPTED,
 281         FR_LOCKED,
 282         FR_PENDING,
 283         FR_SENT,
 284         FR_FINISHED,
 285         FR_PRIVATE,
 286 };
 287
 288 /**
 289  * A request to the client
 290  *
 291  * .waitq.lock protects the following fields:
 292  *   - FR_ABORTED
 293  *   - FR_LOCKED (may also be modified under fc->lock, tested under both)
 294  */
 295 struct fuse_req {
 296         /** This can be on either pending processing or io lists in
 297             fuse_conn */
 298         struct list_head list;
 299
 300         /** Entry on the interrupts list  */
 301         struct list_head intr_entry;
 302
 303         /** refcount */
 304         atomic_t count;
 305
 306         /** Unique ID for the interrupt request */
 307         u64 intr_unique;
 308
 309         /* Request flags, updated with test/set/clear_bit() */
 310         unsigned long flags;
 311
 312         /** The request input */
 313         struct fuse_in in;
 314
 315         /** The request output */
 316         struct fuse_out out;
 317
 318         /** Used to wake up the task waiting for completion of request*/
 319         wait_queue_head_t waitq;
 320
 321         /** Data for asynchronous requests */
 322         union {
 323                 struct {
 324                         struct fuse_release_in in;
 325                         struct inode *inode;
 326                 } release;
 327                 struct fuse_init_in init_in;
 328                 struct fuse_init_out init_out;
 329                 struct cuse_init_in cuse_init_in;
 330                 struct {
 331                         struct fuse_read_in in;
 332                         u64 attr_ver;
 333                 } read;
 334                 struct {
 335                         struct fuse_write_in in;
 336                         struct fuse_write_out out;
 337                         struct fuse_req *next;
 338                 } write;
 339                 struct fuse_notify_retrieve_in retrieve_in;
 340         } misc;
 341
 342         /** page vector */
 343         struct page **pages;
 344
 345         /** page-descriptor vector */
 346         struct fuse_page_desc *page_descs;
 347
 348         /** size of the 'pages' array */
 349         unsigned max_pages;
 350
 351         /** inline page vector */
 352         struct page *inline_pages[FUSE_REQ_INLINE_PAGES];
 353
 354         /** inline page-descriptor vector */
 355         struct fuse_page_desc inline_page_descs[FUSE_REQ_INLINE_PAGES];
 356
 357         /** number of pages in vector */
 358         unsigned num_pages;
 359
 360         /** File used in the request (or NULL) */
 361         struct fuse_file *ff;
 362
 363         /** Inode used in the request or NULL */
 364         struct inode *inode;
 365
 366         /** AIO control block */
 367         struct fuse_io_priv *io;
 368
 369         /** Link on fi->writepages */
 370         struct list_head writepages_entry;
 371
 372         /** Request completion callback */
 373         void (*end)(struct fuse_conn *, struct fuse_req *);
 374
 375         /** Request is stolen from fuse_file->reserved_req */
 376         struct file *stolen_file;
 377 };
 378
 379 struct fuse_iqueue {
 380         /** Connection established */
 381         unsigned connected;
 382
 383         /** Readers of the connection are waiting on this */
 384         wait_queue_head_t waitq;
 385
 386         /** The next unique request id */
 387         u64 reqctr;
 388
 389         /** The list of pending requests */
 390         struct list_head pending;
 391
 392         /** Pending interrupts */
 393         struct list_head interrupts;
 394
 395         /** Queue of pending forgets */
 396         struct fuse_forget_link forget_list_head;
 397         struct fuse_forget_link *forget_list_tail;
 398
 399         /** Batching of FORGET requests (positive indicates FORGET batch) */
 400         int forget_batch;
 401
 402         /** O_ASYNC requests */
 403         struct fasync_struct *fasync;
 404 };
 405
 406 struct fuse_pqueue {
 407         /** Connection established */
 408         unsigned connected;
 409
 410         /** Lock protecting accessess to  members of this structure */
 411         spinlock_t lock;
 412
 413         /** The list of requests being processed */
 414         struct list_head processing;
 415
 416         /** The list of requests under I/O */
 417         struct list_head io;
 418 };
 419
 420 /**
 421  * Fuse device instance
 422  */
 423 struct fuse_dev {
 424         /** Fuse connection for this device */
 425         struct fuse_conn *fc;
 426
 427         /** Processing queue */
 428         struct fuse_pqueue pq;
 429
 430         /** list entry on fc->devices */
 431         struct list_head entry;
 432 };
 433
 434 /**
 435  * A Fuse connection.
 436  *
 437  * This structure is created, when the filesystem is mounted, and is
 438  * destroyed, when the client device is closed and the filesystem is
 439  * unmounted.
 440  */
 441 struct fuse_conn {
 442         /** Lock protecting accessess to  members of this structure */
 443         spinlock_t lock;
 444
 445         /** Refcount */
 446         atomic_t count;
 447
 448         /** Number of fuse_dev's */
 449         atomic_t dev_count;
 450
 451         struct rcu_head rcu;
 452
 453         /** The user id for this mount */
 454         kuid_t user_id;
 455
 456         /** The group id for this mount */
 457         kgid_t group_id;
 458
 459         /** The fuse mount flags for this mount */
 460         unsigned flags;
 461
 462         /** Maximum read size */
 463         unsigned max_read;
 464
 465         /** Maximum write size */
 466         unsigned max_write;
 467
 468         /** Input queue */
 469         struct fuse_iqueue iq;
 470
 471         /** The next unique kernel file handle */
 472         u64 khctr;
 473
 474         /** rbtree of fuse_files waiting for poll events indexed by ph */
 475         struct rb_root polled_files;
 476
 477         /** Maximum number of outstanding background requests */
 478         unsigned max_background;
 479
 480         /** Number of background requests at which congestion starts */
 481         unsigned congestion_threshold;
 482
 483         /** Number of requests currently in the background */
 484         unsigned num_background;
 485
 486         /** Number of background requests currently queued for userspace */
 487         unsigned active_background;
 488
 489         /** The list of background requests set aside for later queuing */
 490         struct list_head bg_queue;
 491
 492         /** Flag indicating that INIT reply has been received. Allocating
 493          * any fuse request will be suspended until the flag is set */
 494         int initialized;
 495
 496         /** Flag indicating if connection is blocked.  This will be
 497             the case before the INIT reply is received, and if there
 498             are too many outstading backgrounds requests */
 499         int blocked;
 500
 501         /** waitq for blocked connection */
 502         wait_queue_head_t blocked_waitq;
 503
 504         /** waitq for reserved requests */
 505         wait_queue_head_t reserved_req_waitq;
 506
 507         /** Connection established, cleared on umount, connection
 508             abort and device release */
 509         unsigned connected;
 510
 511         /** Connection failed (version mismatch).  Cannot race with
 512             setting other bitfields since it is only set once in INIT
 513             reply, before any other request, and never cleared */
 514         unsigned conn_error:1;
 515
 516         /** Connection successful.  Only set in INIT */
 517         unsigned conn_init:1;
 518
 519         /** Do readpages asynchronously?  Only set in INIT */
 520         unsigned async_read:1;
 521
 522         /** Do not send separate SETATTR request before open(O_TRUNC)  */
 523         unsigned atomic_o_trunc:1;
 524
 525         /** Filesystem supports NFS exporting.  Only set in INIT */
 526         unsigned export_support:1;
 527
 528         /** Set if bdi is valid */
 529         unsigned bdi_initialized:1;
 530
 531         /** write-back cache policy (default is write-through) */
 532         unsigned writeback_cache:1;
 533
 534         /*
 535          * The following bitfields are only for optimization purposes
 536          * and hence races in setting them will not cause malfunction
 537          */
 538
 539         /** Is open/release not implemented by fs? */
 540         unsigned no_open:1;
 541
 542         /** Is fsync not implemented by fs? */
 543         unsigned no_fsync:1;
 544
 545         /** Is fsyncdir not implemented by fs? */
 546         unsigned no_fsyncdir:1;
 547
 548         /** Is flush not implemented by fs? */
 549         unsigned no_flush:1;
 550
 551         /** Is setxattr not implemented by fs? */
 552         unsigned no_setxattr:1;
 553
 554         /** Is getxattr not implemented by fs? */
 555         unsigned no_getxattr:1;
 556
 557         /** Is listxattr not implemented by fs? */
 558         unsigned no_listxattr:1;
 559
 560         /** Is removexattr not implemented by fs? */
 561         unsigned no_removexattr:1;
 562
 563         /** Are posix file locking primitives not implemented by fs? */
 564         unsigned no_lock:1;
 565
 566         /** Is access not implemented by fs? */
 567         unsigned no_access:1;
 568
 569         /** Is create not implemented by fs? */
 570         unsigned no_create:1;
 571
 572         /** Is interrupt not implemented by fs? */
 573         unsigned no_interrupt:1;
 574
 575         /** Is bmap not implemented by fs? */
 576         unsigned no_bmap:1;
 577
 578         /** Is poll not implemented by fs? */
 579         unsigned no_poll:1;
 580
 581         /** Do multi-page cached writes */
 582         unsigned big_writes:1;
 583
 584         /** Don't apply umask to creation modes */
 585         unsigned dont_mask:1;
 586
 587         /** Are BSD file locking primitives not implemented by fs? */
 588         unsigned no_flock:1;
 589
 590         /** Is fallocate not implemented by fs? */
 591         unsigned no_fallocate:1;
 592
 593         /** Is rename with flags implemented by fs? */
 594         unsigned no_rename2:1;
 595
 596         /** Use enhanced/automatic page cache invalidation. */
 597         unsigned auto_inval_data:1;
 598
 599         /** Does the filesystem support readdirplus? */
 600         unsigned do_readdirplus:1;
 601
 602         /** Does the filesystem want adaptive readdirplus? */
 603         unsigned readdirplus_auto:1;
 604
 605         /** Does the filesystem support asynchronous direct-IO submission? */
 606         unsigned async_dio:1;
 607
 608         /** The number of requests waiting for completion */
 609         atomic_t num_waiting;
 610
 611         /** Negotiated minor version */
 612         unsigned minor;
 613
 614         /** Backing dev info */
 615         struct backing_dev_info bdi;
 616
 617         /** Entry on the fuse_conn_list */
 618         struct list_head entry;
 619
 620         /** Device ID from super block */
 621         dev_t dev;
 622
 623         /** Dentries in the control filesystem */
 624         struct dentry *ctl_dentry[FUSE_CTL_NUM_DENTRIES];
 625
 626         /** number of dentries used in the above array */
 627         int ctl_ndents;
 628
 629         /** Key for lock owner ID scrambling */
 630         u32 scramble_key[4];
 631
 632         /** Reserved request for the DESTROY message */
 633         struct fuse_req *destroy_req;
 634
 635         /** Version counter for attribute changes */
 636         u64 attr_version;
 637
 638         /** Called on final put */
 639         void (*release)(struct fuse_conn *);
 640
 641         /** Super block for this connection. */
 642         struct super_block *sb;
 643
 644         /** Read/write semaphore to hold when accessing sb. */
 645         struct rw_semaphore killsb;
 646
 647         /** List of device instances belonging to this connection */
 648         struct list_head devices;
 649 };
 650
 651 static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
 652 {
 653         return sb->s_fs_info;
 654 }
 655
 656 static inline struct fuse_conn *get_fuse_conn(struct inode *inode)
 657 {
 658         return get_fuse_conn_super(inode->i_sb);
 659 }
 660
 661 static inline struct fuse_inode *get_fuse_inode(struct inode *inode)
 662 {
 663         return container_of(inode, struct fuse_inode, inode);
 664 }
 665
 666 static inline u64 get_node_id(struct inode *inode)
 667 {
 668         return get_fuse_inode(inode)->nodeid;
 669 }
 670
 671 /** Device operations */
 672 extern const struct file_operations fuse_dev_operations;
 673
 674 extern const struct dentry_operations fuse_dentry_operations;
 675
 676 /**
 677  * Inode to nodeid comparison.
 678  */
 679 int fuse_inode_eq(struct inode *inode, void *_nodeidp);
 680
 681 /**
 682  * Get a filled in inode
 683  */
 684 struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
 685                         int generation, struct fuse_attr *attr,
 686                         u64 attr_valid, u64 attr_version);
 687
 688 int fuse_lookup_name(struct super_block *sb, u64 nodeid, struct qstr *name,
 689                      struct fuse_entry_out *outarg, struct inode **inode);
 690
 691 /**
 692  * Send FORGET command
 693  */
 694 void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget,
 695                        u64 nodeid, u64 nlookup);
 696
 697 struct fuse_forget_link *fuse_alloc_forget(void);
 698
 699 /* Used by READDIRPLUS */
 700 void fuse_force_forget(struct file *file, u64 nodeid);
 701
 702 /**
 703  * Initialize READ or READDIR request
 704  */
 705 void fuse_read_fill(struct fuse_req *req, struct file *file,
 706                     loff_t pos, size_t count, int opcode);
 707
 708 /**
 709  * Send OPEN or OPENDIR request
 710  */
 711 int fuse_open_common(struct inode *inode, struct file *file, bool isdir);
 712
 713 struct fuse_file *fuse_file_alloc(struct fuse_conn *fc);
 714 struct fuse_file *fuse_file_get(struct fuse_file *ff);
 715 void fuse_file_free(struct fuse_file *ff);
 716 void fuse_finish_open(struct inode *inode, struct file *file);
 717
 718 void fuse_sync_release(struct fuse_file *ff, int flags);
 719
 720 /**
 721  * Send RELEASE or RELEASEDIR request
 722  */
 723 void fuse_release_common(struct file *file, int opcode);
 724
 725 /**
 726  * Send FSYNC or FSYNCDIR request
 727  */
 728 int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
 729                       int datasync, int isdir);
 730
 731 /**
 732  * Notify poll wakeup
 733  */
 734 int fuse_notify_poll_wakeup(struct fuse_conn *fc,
 735                             struct fuse_notify_poll_wakeup_out *outarg);
 736
 737 /**
 738  * Initialize file operations on a regular file
 739  */
 740 void fuse_init_file_inode(struct inode *inode);
 741
 742 /**
 743  * Initialize inode operations on regular files and special files
 744  */
 745 void fuse_init_common(struct inode *inode);
 746
 747 /**
 748  * Initialize inode and file operations on a directory
 749  */
 750 void fuse_init_dir(struct inode *inode);
 751
 752 /**
 753  * Initialize inode operations on a symlink
 754  */
 755 void fuse_init_symlink(struct inode *inode);
 756
 757 /**
 758  * Change attributes of an inode
 759  */
 760 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
 761                             u64 attr_valid, u64 attr_version);
 762
 763 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
 764                                    u64 attr_valid);
 765
 766 /**
 767  * Initialize the client device
 768  */
 769 int fuse_dev_init(void);
 770
 771 /**
 772  * Cleanup the client device
 773  */
 774 void fuse_dev_cleanup(void);
 775
 776 int fuse_ctl_init(void);
 777 void __exit fuse_ctl_cleanup(void);
 778
 779 /**
 780  * Allocate a request
 781  */
 782 struct fuse_req *fuse_request_alloc(unsigned npages);
 783
 784 struct fuse_req *fuse_request_alloc_nofs(unsigned npages);
 785
 786 /**
 787  * Free a request
 788  */
 789 void fuse_request_free(struct fuse_req *req);
 790
 791 /**
 792  * Get a request, may fail with -ENOMEM,
 793  * caller should specify # elements in req->pages[] explicitly
 794  */
 795 struct fuse_req *fuse_get_req(struct fuse_conn *fc, unsigned npages);
 796 struct fuse_req *fuse_get_req_for_background(struct fuse_conn *fc,
 797                                              unsigned npages);
 798
 799 /*
 800  * Increment reference count on request
 801  */
 802 void __fuse_get_request(struct fuse_req *req);
 803
 804 /**
 805  * Gets a requests for a file operation, always succeeds
 806  */
 807 struct fuse_req *fuse_get_req_nofail_nopages(struct fuse_conn *fc,
 808                                              struct file *file);
 809
 810 /**
 811  * Decrement reference count of a request.  If count goes to zero free
 812  * the request.
 813  */
 814 void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req);
 815
 816 /**
 817  * Send a request (synchronous)
 818  */
 819 void fuse_request_send(struct fuse_conn *fc, struct fuse_req *req);
 820
 821 /**
 822  * Simple request sending that does request allocation and freeing
 823  */
 824 ssize_t fuse_simple_request(struct fuse_conn *fc, struct fuse_args *args);
 825
 826 /**
 827  * Send a request in the background
 828  */
 829 void fuse_request_send_background(struct fuse_conn *fc, struct fuse_req *req);
 830
 831 void fuse_request_send_background_locked(struct fuse_conn *fc,
 832                                          struct fuse_req *req);
 833
 834 /* Abort all requests */
 835 void fuse_abort_conn(struct fuse_conn *fc);
 836
 837 /**
 838  * Invalidate inode attributes
 839  */
 840 void fuse_invalidate_attr(struct inode *inode);
 841
 842 void fuse_invalidate_entry_cache(struct dentry *entry);
 843
 844 void fuse_invalidate_atime(struct inode *inode);
 845
 846 /**
 847  * Acquire reference to fuse_conn
 848  */
 849 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc);
 850
 851 /**
 852  * Initialize fuse_conn
 853  */
 854 void fuse_conn_init(struct fuse_conn *fc);
 855
 856 /**
 857  * Release reference to fuse_conn
 858  */
 859 void fuse_conn_put(struct fuse_conn *fc);
 860
 861 struct fuse_dev *fuse_dev_alloc(struct fuse_conn *fc);
 862 void fuse_dev_free(struct fuse_dev *fud);
 863
 864 /**
 865  * Add connection to control filesystem
 866  */
 867 int fuse_ctl_add_conn(struct fuse_conn *fc);
 868
 869 /**
 870  * Remove connection from control filesystem
 871  */
 872 void fuse_ctl_remove_conn(struct fuse_conn *fc);
 873
 874 /**
 875  * Is file type valid?
 876  */
 877 int fuse_valid_type(int m);
 878
 879 /**
 880  * Is current process allowed to perform filesystem operation?
 881  */
 882 int fuse_allow_current_process(struct fuse_conn *fc);
 883
 884 u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id);
 885
 886 int fuse_update_attributes(struct inode *inode, struct kstat *stat,
 887                            struct file *file, bool *refreshed);
 888
 889 void fuse_flush_writepages(struct inode *inode);
 890
 891 void fuse_set_nowrite(struct inode *inode);
 892 void fuse_release_nowrite(struct inode *inode);
 893
 894 u64 fuse_get_attr_version(struct fuse_conn *fc);
 895
 896 /**
 897  * File-system tells the kernel to invalidate cache for the given node id.
 898  */
 899 int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
 900                              loff_t offset, loff_t len);
 901
 902 /**
 903  * File-system tells the kernel to invalidate parent attributes and
 904  * the dentry matching parent/name.
 905  *
 906  * If the child_nodeid is non-zero and:
 907  *    - matches the inode number for the dentry matching parent/name,
 908  *    - is not a mount point
 909  *    - is a file or oan empty directory
 910  * then the dentry is unhashed (d_delete()).
 911  */
 912 int fuse_reverse_inval_entry(struct super_block *sb, u64 parent_nodeid,
 913                              u64 child_nodeid, struct qstr *name);
 914
 915 int fuse_do_open(struct fuse_conn *fc, u64 nodeid, struct file *file,
 916                  bool isdir);
 917
 918 /**
 919  * fuse_direct_io() flags
 920  */
 921
 922 /** If set, it is WRITE; otherwise - READ */
 923 #define FUSE_DIO_WRITE (1 << 0)
 924
 925 /** CUSE pass fuse_direct_io() a file which f_mapping->host is not from FUSE */
 926 #define FUSE_DIO_CUSE  (1 << 1)
 927
 928 ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter,
 929                        loff_t *ppos, int flags);
 930 long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
 931                    unsigned int flags);
 932 long fuse_ioctl_common(struct file *file, unsigned int cmd,
 933                        unsigned long arg, unsigned int flags);
 934 unsigned fuse_file_poll(struct file *file, poll_table *wait);
 935 int fuse_dev_release(struct inode *inode, struct file *file);
 936
 937 bool fuse_write_update_size(struct inode *inode, loff_t pos);
 938
 939 int fuse_flush_times(struct inode *inode, struct fuse_file *ff);
 940 int fuse_write_inode(struct inode *inode, struct writeback_control *wbc);
 941
 942 int fuse_do_setattr(struct inode *inode, struct iattr *attr,
 943                     struct file *file);
 944
 945 void fuse_set_initialized(struct fuse_conn *fc);
 946
 947 #endif /* _FS_FUSE_I_H */