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         /** i_mtime has been updated locally; a flush to userspace needed */
 123         FUSE_I_MTIME_DIRTY,
 124 };
 125
 126 struct fuse_conn;
 127
 128 /** FUSE specific file data */
 129 struct fuse_file {
 130         /** Fuse connection for this file */
 131         struct fuse_conn *fc;
 132
 133         /** Request reserved for flush and release */
 134         struct fuse_req *reserved_req;
 135
 136         /** Kernel file handle guaranteed to be unique */
 137         u64 kh;
 138
 139         /** File handle used by userspace */
 140         u64 fh;
 141
 142         /** Node id of this file */
 143         u64 nodeid;
 144
 145         /** Refcount */
 146         atomic_t count;
 147
 148         /** FOPEN_* flags returned by open */
 149         u32 open_flags;
 150
 151         /** Entry on inode's write_files list */
 152         struct list_head write_entry;
 153
 154         /** RB node to be linked on fuse_conn->polled_files */
 155         struct rb_node polled_node;
 156
 157         /** Wait queue head for poll */
 158         wait_queue_head_t poll_wait;
 159
 160         /** Has flock been performed on this file? */
 161         bool flock:1;
 162 };
 163
 164 /** One input argument of a request */
 165 struct fuse_in_arg {
 166         unsigned size;
 167         const void *value;
 168 };
 169
 170 /** The request input */
 171 struct fuse_in {
 172         /** The request header */
 173         struct fuse_in_header h;
 174
 175         /** True if the data for the last argument is in req->pages */
 176         unsigned argpages:1;
 177
 178         /** Number of arguments */
 179         unsigned numargs;
 180
 181         /** Array of arguments */
 182         struct fuse_in_arg args[3];
 183 };
 184
 185 /** One output argument of a request */
 186 struct fuse_arg {
 187         unsigned size;
 188         void *value;
 189 };
 190
 191 /** The request output */
 192 struct fuse_out {
 193         /** Header returned from userspace */
 194         struct fuse_out_header h;
 195
 196         /*
 197          * The following bitfields are not changed during the request
 198          * processing
 199          */
 200
 201         /** Last argument is variable length (can be shorter than
 202             arg->size) */
 203         unsigned argvar:1;
 204
 205         /** Last argument is a list of pages to copy data to */
 206         unsigned argpages:1;
 207
 208         /** Zero partially or not copied pages */
 209         unsigned page_zeroing:1;
 210
 211         /** Pages may be replaced with new ones */
 212         unsigned page_replace:1;
 213
 214         /** Number or arguments */
 215         unsigned numargs;
 216
 217         /** Array of arguments */
 218         struct fuse_arg args[3];
 219 };
 220
 221 /** FUSE page descriptor */
 222 struct fuse_page_desc {
 223         unsigned int length;
 224         unsigned int offset;
 225 };
 226
 227 /** The request state */
 228 enum fuse_req_state {
 229         FUSE_REQ_INIT = 0,
 230         FUSE_REQ_PENDING,
 231         FUSE_REQ_READING,
 232         FUSE_REQ_SENT,
 233         FUSE_REQ_WRITING,
 234         FUSE_REQ_FINISHED
 235 };
 236
 237 /** The request IO state (for asynchronous processing) */
 238 struct fuse_io_priv {
 239         int async;
 240         spinlock_t lock;
 241         unsigned reqs;
 242         ssize_t bytes;
 243         size_t size;
 244         __u64 offset;
 245         bool write;
 246         int err;
 247         struct kiocb *iocb;
 248         struct file *file;
 249 };
 250
 251 /**
 252  * A request to the client
 253  */
 254 struct fuse_req {
 255         /** This can be on either pending processing or io lists in
 256             fuse_conn */
 257         struct list_head list;
 258
 259         /** Entry on the interrupts list  */
 260         struct list_head intr_entry;
 261
 262         /** refcount */
 263         atomic_t count;
 264
 265         /** Unique ID for the interrupt request */
 266         u64 intr_unique;
 267
 268         /*
 269          * The following bitfields are either set once before the
 270          * request is queued or setting/clearing them is protected by
 271          * fuse_conn->lock
 272          */
 273
 274         /** True if the request has reply */
 275         unsigned isreply:1;
 276
 277         /** Force sending of the request even if interrupted */
 278         unsigned force:1;
 279
 280         /** The request was aborted */
 281         unsigned aborted:1;
 282
 283         /** Request is sent in the background */
 284         unsigned background:1;
 285
 286         /** The request has been interrupted */
 287         unsigned interrupted:1;
 288
 289         /** Data is being copied to/from the request */
 290         unsigned locked:1;
 291
 292         /** Request is counted as "waiting" */
 293         unsigned waiting:1;
 294
 295         /** State of the request */
 296         enum fuse_req_state state;
 297
 298         /** The request input */
 299         struct fuse_in in;
 300
 301         /** The request output */
 302         struct fuse_out out;
 303
 304         /** Used to wake up the task waiting for completion of request*/
 305         wait_queue_head_t waitq;
 306
 307         /** Data for asynchronous requests */
 308         union {
 309                 struct {
 310                         union {
 311                                 struct fuse_release_in in;
 312                                 struct work_struct work;
 313                         };
 314                         struct path path;
 315                 } release;
 316                 struct fuse_init_in init_in;
 317                 struct fuse_init_out init_out;
 318                 struct cuse_init_in cuse_init_in;
 319                 struct {
 320                         struct fuse_read_in in;
 321                         u64 attr_ver;
 322                 } read;
 323                 struct {
 324                         struct fuse_write_in in;
 325                         struct fuse_write_out out;
 326                         struct fuse_req *next;
 327                 } write;
 328                 struct fuse_notify_retrieve_in retrieve_in;
 329                 struct fuse_lk_in lk_in;
 330         } misc;
 331
 332         /** page vector */
 333         struct page **pages;
 334
 335         /** page-descriptor vector */
 336         struct fuse_page_desc *page_descs;
 337
 338         /** size of the 'pages' array */
 339         unsigned max_pages;
 340
 341         /** inline page vector */
 342         struct page *inline_pages[FUSE_REQ_INLINE_PAGES];
 343
 344         /** inline page-descriptor vector */
 345         struct fuse_page_desc inline_page_descs[FUSE_REQ_INLINE_PAGES];
 346
 347         /** number of pages in vector */
 348         unsigned num_pages;
 349
 350         /** File used in the request (or NULL) */
 351         struct fuse_file *ff;
 352
 353         /** Inode used in the request or NULL */
 354         struct inode *inode;
 355
 356         /** AIO control block */
 357         struct fuse_io_priv *io;
 358
 359         /** Link on fi->writepages */
 360         struct list_head writepages_entry;
 361
 362         /** Request completion callback */
 363         void (*end)(struct fuse_conn *, struct fuse_req *);
 364
 365         /** Request is stolen from fuse_file->reserved_req */
 366         struct file *stolen_file;
 367 };
 368
 369 /**
 370  * A Fuse connection.
 371  *
 372  * This structure is created, when the filesystem is mounted, and is
 373  * destroyed, when the client device is closed and the filesystem is
 374  * unmounted.
 375  */
 376 struct fuse_conn {
 377         /** Lock protecting accessess to  members of this structure */
 378         spinlock_t lock;
 379
 380         /** Refcount */
 381         atomic_t count;
 382
 383         struct rcu_head rcu;
 384
 385         /** The user id for this mount */
 386         kuid_t user_id;
 387
 388         /** The group id for this mount */
 389         kgid_t group_id;
 390
 391         /** The fuse mount flags for this mount */
 392         unsigned flags;
 393
 394         /** Maximum read size */
 395         unsigned max_read;
 396
 397         /** Maximum write size */
 398         unsigned max_write;
 399
 400         /** Readers of the connection are waiting on this */
 401         wait_queue_head_t waitq;
 402
 403         /** The list of pending requests */
 404         struct list_head pending;
 405
 406         /** The list of requests being processed */
 407         struct list_head processing;
 408
 409         /** The list of requests under I/O */
 410         struct list_head io;
 411
 412         /** The next unique kernel file handle */
 413         u64 khctr;
 414
 415         /** rbtree of fuse_files waiting for poll events indexed by ph */
 416         struct rb_root polled_files;
 417
 418         /** Maximum number of outstanding background requests */
 419         unsigned max_background;
 420
 421         /** Number of background requests at which congestion starts */
 422         unsigned congestion_threshold;
 423
 424         /** Number of requests currently in the background */
 425         unsigned num_background;
 426
 427         /** Number of background requests currently queued for userspace */
 428         unsigned active_background;
 429
 430         /** The list of background requests set aside for later queuing */
 431         struct list_head bg_queue;
 432
 433         /** Pending interrupts */
 434         struct list_head interrupts;
 435
 436         /** Queue of pending forgets */
 437         struct fuse_forget_link forget_list_head;
 438         struct fuse_forget_link *forget_list_tail;
 439
 440         /** Batching of FORGET requests (positive indicates FORGET batch) */
 441         int forget_batch;
 442
 443         /** Flag indicating that INIT reply has been received. Allocating
 444          * any fuse request will be suspended until the flag is set */
 445         int initialized;
 446
 447         /** Flag indicating if connection is blocked.  This will be
 448             the case before the INIT reply is received, and if there
 449             are too many outstading backgrounds requests */
 450         int blocked;
 451
 452         /** waitq for blocked connection */
 453         wait_queue_head_t blocked_waitq;
 454
 455         /** waitq for reserved requests */
 456         wait_queue_head_t reserved_req_waitq;
 457
 458         /** The next unique request id */
 459         u64 reqctr;
 460
 461         /** Connection established, cleared on umount, connection
 462             abort and device release */
 463         unsigned connected;
 464
 465         /** Connection failed (version mismatch).  Cannot race with
 466             setting other bitfields since it is only set once in INIT
 467             reply, before any other request, and never cleared */
 468         unsigned conn_error:1;
 469
 470         /** Connection successful.  Only set in INIT */
 471         unsigned conn_init:1;
 472
 473         /** Do readpages asynchronously?  Only set in INIT */
 474         unsigned async_read:1;
 475
 476         /** Do not send separate SETATTR request before open(O_TRUNC)  */
 477         unsigned atomic_o_trunc:1;
 478
 479         /** Filesystem supports NFS exporting.  Only set in INIT */
 480         unsigned export_support:1;
 481
 482         /** Set if bdi is valid */
 483         unsigned bdi_initialized:1;
 484
 485         /** write-back cache policy (default is write-through) */
 486         unsigned writeback_cache:1;
 487
 488         /*
 489          * The following bitfields are only for optimization purposes
 490          * and hence races in setting them will not cause malfunction
 491          */
 492
 493         /** Is open/release not implemented by fs? */
 494         unsigned no_open:1;
 495
 496         /** Is fsync not implemented by fs? */
 497         unsigned no_fsync:1;
 498
 499         /** Is fsyncdir not implemented by fs? */
 500         unsigned no_fsyncdir:1;
 501
 502         /** Is flush not implemented by fs? */
 503         unsigned no_flush:1;
 504
 505         /** Is setxattr not implemented by fs? */
 506         unsigned no_setxattr:1;
 507
 508         /** Is getxattr not implemented by fs? */
 509         unsigned no_getxattr:1;
 510
 511         /** Is listxattr not implemented by fs? */
 512         unsigned no_listxattr:1;
 513
 514         /** Is removexattr not implemented by fs? */
 515         unsigned no_removexattr:1;
 516
 517         /** Are posix file locking primitives not implemented by fs? */
 518         unsigned no_lock:1;
 519
 520         /** Is access not implemented by fs? */
 521         unsigned no_access:1;
 522
 523         /** Is create not implemented by fs? */
 524         unsigned no_create:1;
 525
 526         /** Is interrupt not implemented by fs? */
 527         unsigned no_interrupt:1;
 528
 529         /** Is bmap not implemented by fs? */
 530         unsigned no_bmap:1;
 531
 532         /** Is poll not implemented by fs? */
 533         unsigned no_poll:1;
 534
 535         /** Do multi-page cached writes */
 536         unsigned big_writes:1;
 537
 538         /** Don't apply umask to creation modes */
 539         unsigned dont_mask:1;
 540
 541         /** Are BSD file locking primitives not implemented by fs? */
 542         unsigned no_flock:1;
 543
 544         /** Is fallocate not implemented by fs? */
 545         unsigned no_fallocate:1;
 546
 547         /** Use enhanced/automatic page cache invalidation. */
 548         unsigned auto_inval_data:1;
 549
 550         /** Does the filesystem support readdirplus? */
 551         unsigned do_readdirplus:1;
 552
 553         /** Does the filesystem want adaptive readdirplus? */
 554         unsigned readdirplus_auto:1;
 555
 556         /** Does the filesystem support asynchronous direct-IO submission? */
 557         unsigned async_dio:1;
 558
 559         /** The number of requests waiting for completion */
 560         atomic_t num_waiting;
 561
 562         /** Negotiated minor version */
 563         unsigned minor;
 564
 565         /** Backing dev info */
 566         struct backing_dev_info bdi;
 567
 568         /** Entry on the fuse_conn_list */
 569         struct list_head entry;
 570
 571         /** Device ID from super block */
 572         dev_t dev;
 573
 574         /** Dentries in the control filesystem */
 575         struct dentry *ctl_dentry[FUSE_CTL_NUM_DENTRIES];
 576
 577         /** number of dentries used in the above array */
 578         int ctl_ndents;
 579
 580         /** O_ASYNC requests */
 581         struct fasync_struct *fasync;
 582
 583         /** Key for lock owner ID scrambling */
 584         u32 scramble_key[4];
 585
 586         /** Reserved request for the DESTROY message */
 587         struct fuse_req *destroy_req;
 588
 589         /** Version counter for attribute changes */
 590         u64 attr_version;
 591
 592         /** Called on final put */
 593         void (*release)(struct fuse_conn *);
 594
 595         /** Super block for this connection. */
 596         struct super_block *sb;
 597
 598         /** Read/write semaphore to hold when accessing sb. */
 599         struct rw_semaphore killsb;
 600 };
 601
 602 static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
 603 {
 604         return sb->s_fs_info;
 605 }
 606
 607 static inline struct fuse_conn *get_fuse_conn(struct inode *inode)
 608 {
 609         return get_fuse_conn_super(inode->i_sb);
 610 }
 611
 612 static inline struct fuse_inode *get_fuse_inode(struct inode *inode)
 613 {
 614         return container_of(inode, struct fuse_inode, inode);
 615 }
 616
 617 static inline u64 get_node_id(struct inode *inode)
 618 {
 619         return get_fuse_inode(inode)->nodeid;
 620 }
 621
 622 /** Device operations */
 623 extern const struct file_operations fuse_dev_operations;
 624
 625 extern const struct dentry_operations fuse_dentry_operations;
 626
 627 /**
 628  * Inode to nodeid comparison.
 629  */
 630 int fuse_inode_eq(struct inode *inode, void *_nodeidp);
 631
 632 /**
 633  * Get a filled in inode
 634  */
 635 struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
 636                         int generation, struct fuse_attr *attr,
 637                         u64 attr_valid, u64 attr_version);
 638
 639 int fuse_lookup_name(struct super_block *sb, u64 nodeid, struct qstr *name,
 640                      struct fuse_entry_out *outarg, struct inode **inode);
 641
 642 /**
 643  * Send FORGET command
 644  */
 645 void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget,
 646                        u64 nodeid, u64 nlookup);
 647
 648 struct fuse_forget_link *fuse_alloc_forget(void);
 649
 650 /* Used by READDIRPLUS */
 651 void fuse_force_forget(struct file *file, u64 nodeid);
 652
 653 /**
 654  * Initialize READ or READDIR request
 655  */
 656 void fuse_read_fill(struct fuse_req *req, struct file *file,
 657                     loff_t pos, size_t count, int opcode);
 658
 659 /**
 660  * Send OPEN or OPENDIR request
 661  */
 662 int fuse_open_common(struct inode *inode, struct file *file, bool isdir);
 663
 664 struct fuse_file *fuse_file_alloc(struct fuse_conn *fc);
 665 struct fuse_file *fuse_file_get(struct fuse_file *ff);
 666 void fuse_file_free(struct fuse_file *ff);
 667 void fuse_finish_open(struct inode *inode, struct file *file);
 668
 669 void fuse_sync_release(struct fuse_file *ff, int flags);
 670
 671 /**
 672  * Send RELEASE or RELEASEDIR request
 673  */
 674 void fuse_release_common(struct file *file, int opcode);
 675
 676 /**
 677  * Send FSYNC or FSYNCDIR request
 678  */
 679 int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
 680                       int datasync, int isdir);
 681
 682 /**
 683  * Notify poll wakeup
 684  */
 685 int fuse_notify_poll_wakeup(struct fuse_conn *fc,
 686                             struct fuse_notify_poll_wakeup_out *outarg);
 687
 688 /**
 689  * Initialize file operations on a regular file
 690  */
 691 void fuse_init_file_inode(struct inode *inode);
 692
 693 /**
 694  * Initialize inode operations on regular files and special files
 695  */
 696 void fuse_init_common(struct inode *inode);
 697
 698 /**
 699  * Initialize inode and file operations on a directory
 700  */
 701 void fuse_init_dir(struct inode *inode);
 702
 703 /**
 704  * Initialize inode operations on a symlink
 705  */
 706 void fuse_init_symlink(struct inode *inode);
 707
 708 /**
 709  * Change attributes of an inode
 710  */
 711 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
 712                             u64 attr_valid, u64 attr_version);
 713
 714 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
 715                                    u64 attr_valid);
 716
 717 /**
 718  * Initialize the client device
 719  */
 720 int fuse_dev_init(void);
 721
 722 /**
 723  * Cleanup the client device
 724  */
 725 void fuse_dev_cleanup(void);
 726
 727 int fuse_ctl_init(void);
 728 void fuse_ctl_cleanup(void);
 729
 730 /**
 731  * Allocate a request
 732  */
 733 struct fuse_req *fuse_request_alloc(unsigned npages);
 734
 735 struct fuse_req *fuse_request_alloc_nofs(unsigned npages);
 736
 737 /**
 738  * Free a request
 739  */
 740 void fuse_request_free(struct fuse_req *req);
 741
 742 /**
 743  * Get a request, may fail with -ENOMEM,
 744  * caller should specify # elements in req->pages[] explicitly
 745  */
 746 struct fuse_req *fuse_get_req(struct fuse_conn *fc, unsigned npages);
 747 struct fuse_req *fuse_get_req_for_background(struct fuse_conn *fc,
 748                                              unsigned npages);
 749
 750 /*
 751  * Increment reference count on request
 752  */
 753 void __fuse_get_request(struct fuse_req *req);
 754
 755 /**
 756  * Get a request, may fail with -ENOMEM,
 757  * useful for callers who doesn't use req->pages[]
 758  */
 759 static inline struct fuse_req *fuse_get_req_nopages(struct fuse_conn *fc)
 760 {
 761         return fuse_get_req(fc, 0);
 762 }
 763
 764 /**
 765  * Gets a requests for a file operation, always succeeds
 766  */
 767 struct fuse_req *fuse_get_req_nofail_nopages(struct fuse_conn *fc,
 768                                              struct file *file);
 769
 770 /**
 771  * Decrement reference count of a request.  If count goes to zero free
 772  * the request.
 773  */
 774 void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req);
 775
 776 /**
 777  * Send a request (synchronous)
 778  */
 779 void fuse_request_send(struct fuse_conn *fc, struct fuse_req *req);
 780
 781 /**
 782  * Send a request in the background
 783  */
 784 void fuse_request_send_background(struct fuse_conn *fc, struct fuse_req *req);
 785
 786 void fuse_request_send_background_locked(struct fuse_conn *fc,
 787                                          struct fuse_req *req);
 788
 789 /* Abort all requests */
 790 void fuse_abort_conn(struct fuse_conn *fc);
 791
 792 /**
 793  * Invalidate inode attributes
 794  */
 795 void fuse_invalidate_attr(struct inode *inode);
 796
 797 void fuse_invalidate_entry_cache(struct dentry *entry);
 798
 799 void fuse_invalidate_atime(struct inode *inode);
 800
 801 /**
 802  * Acquire reference to fuse_conn
 803  */
 804 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc);
 805
 806 void fuse_conn_kill(struct fuse_conn *fc);
 807
 808 /**
 809  * Initialize fuse_conn
 810  */
 811 void fuse_conn_init(struct fuse_conn *fc);
 812
 813 /**
 814  * Release reference to fuse_conn
 815  */
 816 void fuse_conn_put(struct fuse_conn *fc);
 817
 818 /**
 819  * Add connection to control filesystem
 820  */
 821 int fuse_ctl_add_conn(struct fuse_conn *fc);
 822
 823 /**
 824  * Remove connection from control filesystem
 825  */
 826 void fuse_ctl_remove_conn(struct fuse_conn *fc);
 827
 828 /**
 829  * Is file type valid?
 830  */
 831 int fuse_valid_type(int m);
 832
 833 /**
 834  * Is current process allowed to perform filesystem operation?
 835  */
 836 int fuse_allow_current_process(struct fuse_conn *fc);
 837
 838 u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id);
 839
 840 int fuse_update_attributes(struct inode *inode, struct kstat *stat,
 841                            struct file *file, bool *refreshed);
 842
 843 void fuse_flush_writepages(struct inode *inode);
 844
 845 void fuse_set_nowrite(struct inode *inode);
 846 void fuse_release_nowrite(struct inode *inode);
 847
 848 u64 fuse_get_attr_version(struct fuse_conn *fc);
 849
 850 /**
 851  * File-system tells the kernel to invalidate cache for the given node id.
 852  */
 853 int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
 854                              loff_t offset, loff_t len);
 855
 856 /**
 857  * File-system tells the kernel to invalidate parent attributes and
 858  * the dentry matching parent/name.
 859  *
 860  * If the child_nodeid is non-zero and:
 861  *    - matches the inode number for the dentry matching parent/name,
 862  *    - is not a mount point
 863  *    - is a file or oan empty directory
 864  * then the dentry is unhashed (d_delete()).
 865  */
 866 int fuse_reverse_inval_entry(struct super_block *sb, u64 parent_nodeid,
 867                              u64 child_nodeid, struct qstr *name);
 868
 869 int fuse_do_open(struct fuse_conn *fc, u64 nodeid, struct file *file,
 870                  bool isdir);
 871
 872 /**
 873  * fuse_direct_io() flags
 874  */
 875
 876 /** If set, it is WRITE; otherwise - READ */
 877 #define FUSE_DIO_WRITE (1 << 0)
 878
 879 /** CUSE pass fuse_direct_io() a file which f_mapping->host is not from FUSE */
 880 #define FUSE_DIO_CUSE  (1 << 1)
 881
 882 ssize_t fuse_direct_io(struct fuse_io_priv *io, const struct iovec *iov,
 883                        unsigned long nr_segs, size_t count, loff_t *ppos,
 884                        int flags);
 885 long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
 886                    unsigned int flags);
 887 long fuse_ioctl_common(struct file *file, unsigned int cmd,
 888                        unsigned long arg, unsigned int flags);
 889 unsigned fuse_file_poll(struct file *file, poll_table *wait);
 890 int fuse_dev_release(struct inode *inode, struct file *file);
 891
 892 bool fuse_write_update_size(struct inode *inode, loff_t pos);
 893
 894 int fuse_flush_mtime(struct file *file, bool nofail);
 895
 896 int fuse_do_setattr(struct inode *inode, struct iattr *attr,
 897                     struct file *file);
 898
 899 #endif /* _FS_FUSE_I_H */