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 #include <linux/kref.h>
  26
  27 /** Max number of pages that can be used in a single read request */
  28 #define FUSE_MAX_PAGES_PER_REQ 32
  29
  30 /** Bias for fi->writectr, meaning new writepages must not be sent */
  31 #define FUSE_NOWRITE INT_MIN
  32
  33 /** It could be as large as PATH_MAX, but would that have any uses? */
  34 #define FUSE_NAME_MAX 1024
  35
  36 /** Number of dentries for each connection in the control filesystem */
  37 #define FUSE_CTL_NUM_DENTRIES 5
  38
  39 /** If the FUSE_DEFAULT_PERMISSIONS flag is given, the filesystem
  40     module will check permissions based on the file mode.  Otherwise no
  41     permission checking is done in the kernel */
  42 #define FUSE_DEFAULT_PERMISSIONS (1 << 0)
  43
  44 /** If the FUSE_ALLOW_OTHER flag is given, then not only the user
  45     doing the mount will be allowed to access the filesystem */
  46 #define FUSE_ALLOW_OTHER         (1 << 1)
  47
  48 /** Number of page pointers embedded in fuse_req */
  49 #define FUSE_REQ_INLINE_PAGES 1
  50
  51 /** List of active connections */
  52 extern struct list_head fuse_conn_list;
  53
  54 /** Global mutex protecting fuse_conn_list and the control filesystem */
  55 extern struct mutex fuse_mutex;
  56
  57 /** Module parameters */
  58 extern unsigned max_user_bgreq;
  59 extern unsigned max_user_congthresh;
  60
  61 /* One forget request */
  62 struct fuse_forget_link {
  63         struct fuse_forget_one forget_one;
  64         struct fuse_forget_link *next;
  65 };
  66
  67 /** FUSE inode */
  68 struct fuse_inode {
  69         /** Inode data */
  70         struct inode inode;
  71
  72         /** Unique ID, which identifies the inode between userspace
  73          * and kernel */
  74         u64 nodeid;
  75
  76         /** Number of lookups on this inode */
  77         u64 nlookup;
  78
  79         /** The request used for sending the FORGET message */
  80         struct fuse_forget_link *forget;
  81
  82         /** Time in jiffies until the file attributes are valid */
  83         u64 i_time;
  84
  85         /** The sticky bit in inode->i_mode may have been removed, so
  86             preserve the original mode */
  87         umode_t orig_i_mode;
  88
  89         /** 64 bit inode number */
  90         u64 orig_ino;
  91
  92         /** Version of last attribute change */
  93         u64 attr_version;
  94
  95         /** Files usable in writepage.  Protected by fc->lock */
  96         struct list_head write_files;
  97
  98         /** Writepages pending on truncate or fsync */
  99         struct list_head queued_writes;
 100
 101         /** Number of sent writes, a negative bias (FUSE_NOWRITE)
 102          * means more writes are blocked */
 103         int writectr;
 104
 105         /** Waitq for writepage completion */
 106         wait_queue_head_t page_waitq;
 107
 108         /** List of writepage requestst (pending or sent) */
 109         struct list_head writepages;
 110
 111         /** Miscellaneous bits describing inode state */
 112         unsigned long state;
 113 };
 114
 115 /** FUSE inode state bits */
 116 enum {
 117         /** Advise readdirplus  */
 118         FUSE_I_ADVISE_RDPLUS,
 119         /** Initialized with readdirplus */
 120         FUSE_I_INIT_RDPLUS,
 121         /** An operation changing file size is in progress  */
 122         FUSE_I_SIZE_UNSTABLE,
 123 };
 124
 125 struct fuse_conn;
 126
 127 /** FUSE specific file data */
 128 struct fuse_file {
 129         /** Fuse connection for this file */
 130         struct fuse_conn *fc;
 131
 132         /** Request reserved for flush and release */
 133         struct fuse_req *reserved_req;
 134
 135         /** Kernel file handle guaranteed to be unique */
 136         u64 kh;
 137
 138         /** File handle used by userspace */
 139         u64 fh;
 140
 141         /** Node id of this file */
 142         u64 nodeid;
 143
 144         /** Refcount */
 145         atomic_t count;
 146
 147         /** FOPEN_* flags returned by open */
 148         u32 open_flags;
 149
 150         /** Entry on inode's write_files list */
 151         struct list_head write_entry;
 152
 153         /** RB node to be linked on fuse_conn->polled_files */
 154         struct rb_node polled_node;
 155
 156         /** Wait queue head for poll */
 157         wait_queue_head_t poll_wait;
 158
 159         /** Has flock been performed on this file? */
 160         bool flock:1;
 161 };
 162
 163 /** One input argument of a request */
 164 struct fuse_in_arg {
 165         unsigned size;
 166         const void *value;
 167 };
 168
 169 /** The request input */
 170 struct fuse_in {
 171         /** The request header */
 172         struct fuse_in_header h;
 173
 174         /** True if the data for the last argument is in req->pages */
 175         unsigned argpages:1;
 176
 177         /** Number of arguments */
 178         unsigned numargs;
 179
 180         /** Array of arguments */
 181         struct fuse_in_arg args[3];
 182 };
 183
 184 /** One output argument of a request */
 185 struct fuse_arg {
 186         unsigned size;
 187         void *value;
 188 };
 189
 190 /** The request output */
 191 struct fuse_out {
 192         /** Header returned from userspace */
 193         struct fuse_out_header h;
 194
 195         /*
 196          * The following bitfields are not changed during the request
 197          * processing
 198          */
 199
 200         /** Last argument is variable length (can be shorter than
 201             arg->size) */
 202         unsigned argvar:1;
 203
 204         /** Last argument is a list of pages to copy data to */
 205         unsigned argpages:1;
 206
 207         /** Zero partially or not copied pages */
 208         unsigned page_zeroing:1;
 209
 210         /** Pages may be replaced with new ones */
 211         unsigned page_replace:1;
 212
 213         /** Number or arguments */
 214         unsigned numargs;
 215
 216         /** Array of arguments */
 217         struct fuse_arg args[2];
 218 };
 219
 220 /** FUSE page descriptor */
 221 struct fuse_page_desc {
 222         unsigned int length;
 223         unsigned int offset;
 224 };
 225
 226 struct fuse_args {
 227         struct {
 228                 struct {
 229                         uint32_t opcode;
 230                         uint64_t nodeid;
 231                 } h;
 232                 unsigned numargs;
 233                 struct fuse_in_arg args[3];
 234
 235         } in;
 236         struct {
 237                 unsigned argvar:1;
 238                 unsigned numargs;
 239                 struct fuse_arg args[2];
 240         } out;
 241 };
 242
 243 #define FUSE_ARGS(args) struct fuse_args args = {}
 244
 245 /** The request IO state (for asynchronous processing) */
 246 struct fuse_io_priv {
 247         struct kref refcnt;
 248         int async;
 249         spinlock_t lock;
 250         unsigned reqs;
 251         ssize_t bytes;
 252         size_t size;
 253         __u64 offset;
 254         bool write;
 255         int err;
 256         struct kiocb *iocb;
 257         struct file *file;
 258         struct completion *done;
 259 };
 260
 261 #define FUSE_IO_PRIV_SYNC(f) \
 262 {                                       \
 263         .refcnt = { ATOMIC_INIT(1) },   \
 264         .async = 0,                     \
 265         .file = f,                      \
 266 }
 267
 268 /**
 269  * Request flags
 270  *
 271  * FR_ISREPLY:          set if the request has reply
 272  * FR_FORCE:            force sending of the request even if interrupted
 273  * FR_BACKGROUND:       request is sent in the background
 274  * FR_WAITING:          request is counted as "waiting"
 275  * FR_ABORTED:          the request was aborted
 276  * FR_INTERRUPTED:      the request has been interrupted
 277  * FR_LOCKED:           data is being copied to/from the request
 278  * FR_PENDING:          request is not yet in userspace
 279  * FR_SENT:             request is in userspace, waiting for an answer
 280  * FR_FINISHED:         request is finished
 281  * FR_PRIVATE:          request is on private list
 282  */
 283 enum fuse_req_flag {
 284         FR_ISREPLY,
 285         FR_FORCE,
 286         FR_BACKGROUND,
 287         FR_WAITING,
 288         FR_ABORTED,
 289         FR_INTERRUPTED,
 290         FR_LOCKED,
 291         FR_PENDING,
 292         FR_SENT,
 293         FR_FINISHED,
 294         FR_PRIVATE,
 295 };
 296
 297 /**
 298  * A request to the client
 299  *
 300  * .waitq.lock protects the following fields:
 301  *   - FR_ABORTED
 302  *   - FR_LOCKED (may also be modified under fc->lock, tested under both)
 303  */
 304 struct fuse_req {
 305         /** This can be on either pending processing or io lists in
 306             fuse_conn */
 307         struct list_head list;
 308
 309         /** Entry on the interrupts list  */
 310         struct list_head intr_entry;
 311
 312         /** refcount */
 313         atomic_t count;
 314
 315         /** Unique ID for the interrupt request */
 316         u64 intr_unique;
 317
 318         /* Request flags, updated with test/set/clear_bit() */
 319         unsigned long flags;
 320
 321         /** The request input */
 322         struct fuse_in in;
 323
 324         /** The request output */
 325         struct fuse_out out;
 326
 327         /** Used to wake up the task waiting for completion of request*/
 328         wait_queue_head_t waitq;
 329
 330         /** Data for asynchronous requests */
 331         union {
 332                 struct {
 333                         struct fuse_release_in in;
 334                         struct inode *inode;
 335                 } release;
 336                 struct fuse_init_in init_in;
 337                 struct fuse_init_out init_out;
 338                 struct cuse_init_in cuse_init_in;
 339                 struct {
 340                         struct fuse_read_in in;
 341                         u64 attr_ver;
 342                 } read;
 343                 struct {
 344                         struct fuse_write_in in;
 345                         struct fuse_write_out out;
 346                         struct fuse_req *next;
 347                 } write;
 348                 struct fuse_notify_retrieve_in retrieve_in;
 349         } misc;
 350
 351         /** page vector */
 352         struct page **pages;
 353
 354         /** page-descriptor vector */
 355         struct fuse_page_desc *page_descs;
 356
 357         /** size of the 'pages' array */
 358         unsigned max_pages;
 359
 360         /** inline page vector */
 361         struct page *inline_pages[FUSE_REQ_INLINE_PAGES];
 362
 363         /** inline page-descriptor vector */
 364         struct fuse_page_desc inline_page_descs[FUSE_REQ_INLINE_PAGES];
 365
 366         /** number of pages in vector */
 367         unsigned num_pages;
 368
 369         /** File used in the request (or NULL) */
 370         struct fuse_file *ff;
 371
 372         /** Inode used in the request or NULL */
 373         struct inode *inode;
 374
 375         /** AIO control block */
 376         struct fuse_io_priv *io;
 377
 378         /** Link on fi->writepages */
 379         struct list_head writepages_entry;
 380
 381         /** Request completion callback */
 382         void (*end)(struct fuse_conn *, struct fuse_req *);
 383
 384         /** Request is stolen from fuse_file->reserved_req */
 385         struct file *stolen_file;
 386 };
 387
 388 struct fuse_iqueue {
 389         /** Connection established */
 390         unsigned connected;
 391
 392         /** Readers of the connection are waiting on this */
 393         wait_queue_head_t waitq;
 394
 395         /** The next unique request id */
 396         u64 reqctr;
 397
 398         /** The list of pending requests */
 399         struct list_head pending;
 400
 401         /** Pending interrupts */
 402         struct list_head interrupts;
 403
 404         /** Queue of pending forgets */
 405         struct fuse_forget_link forget_list_head;
 406         struct fuse_forget_link *forget_list_tail;
 407
 408         /** Batching of FORGET requests (positive indicates FORGET batch) */
 409         int forget_batch;
 410
 411         /** O_ASYNC requests */
 412         struct fasync_struct *fasync;
 413 };
 414
 415 struct fuse_pqueue {
 416         /** Connection established */
 417         unsigned connected;
 418
 419         /** Lock protecting accessess to  members of this structure */
 420         spinlock_t lock;
 421
 422         /** The list of requests being processed */
 423         struct list_head processing;
 424
 425         /** The list of requests under I/O */
 426         struct list_head io;
 427 };
 428
 429 /**
 430  * Fuse device instance
 431  */
 432 struct fuse_dev {
 433         /** Fuse connection for this device */
 434         struct fuse_conn *fc;
 435
 436         /** Processing queue */
 437         struct fuse_pqueue pq;
 438
 439         /** list entry on fc->devices */
 440         struct list_head entry;
 441 };
 442
 443 /**
 444  * A Fuse connection.
 445  *
 446  * This structure is created, when the filesystem is mounted, and is
 447  * destroyed, when the client device is closed and the filesystem is
 448  * unmounted.
 449  */
 450 struct fuse_conn {
 451         /** Lock protecting accessess to  members of this structure */
 452         spinlock_t lock;
 453
 454         /** Refcount */
 455         atomic_t count;
 456
 457         /** Number of fuse_dev's */
 458         atomic_t dev_count;
 459
 460         struct rcu_head rcu;
 461
 462         /** The user id for this mount */
 463         kuid_t user_id;
 464
 465         /** The group id for this mount */
 466         kgid_t group_id;
 467
 468         /** The fuse mount flags for this mount */
 469         unsigned flags;
 470
 471         /** Maximum read size */
 472         unsigned max_read;
 473
 474         /** Maximum write size */
 475         unsigned max_write;
 476
 477         /** Input queue */
 478         struct fuse_iqueue iq;
 479
 480         /** The next unique kernel file handle */
 481         u64 khctr;
 482
 483         /** rbtree of fuse_files waiting for poll events indexed by ph */
 484         struct rb_root polled_files;
 485
 486         /** Maximum number of outstanding background requests */
 487         unsigned max_background;
 488
 489         /** Number of background requests at which congestion starts */
 490         unsigned congestion_threshold;
 491
 492         /** Number of requests currently in the background */
 493         unsigned num_background;
 494
 495         /** Number of background requests currently queued for userspace */
 496         unsigned active_background;
 497
 498         /** The list of background requests set aside for later queuing */
 499         struct list_head bg_queue;
 500
 501         /** Flag indicating that INIT reply has been received. Allocating
 502          * any fuse request will be suspended until the flag is set */
 503         int initialized;
 504
 505         /** Flag indicating if connection is blocked.  This will be
 506             the case before the INIT reply is received, and if there
 507             are too many outstading backgrounds requests */
 508         int blocked;
 509
 510         /** waitq for blocked connection */
 511         wait_queue_head_t blocked_waitq;
 512
 513         /** waitq for reserved requests */
 514         wait_queue_head_t reserved_req_waitq;
 515
 516         /** Connection established, cleared on umount, connection
 517             abort and device release */
 518         unsigned connected;
 519
 520         /** Connection failed (version mismatch).  Cannot race with
 521             setting other bitfields since it is only set once in INIT
 522             reply, before any other request, and never cleared */
 523         unsigned conn_error:1;
 524
 525         /** Connection successful.  Only set in INIT */
 526         unsigned conn_init:1;
 527
 528         /** Do readpages asynchronously?  Only set in INIT */
 529         unsigned async_read:1;
 530
 531         /** Do not send separate SETATTR request before open(O_TRUNC)  */
 532         unsigned atomic_o_trunc:1;
 533
 534         /** Filesystem supports NFS exporting.  Only set in INIT */
 535         unsigned export_support:1;
 536
 537         /** Set if bdi is valid */
 538         unsigned bdi_initialized:1;
 539
 540         /** write-back cache policy (default is write-through) */
 541         unsigned writeback_cache:1;
 542
 543         /*
 544          * The following bitfields are only for optimization purposes
 545          * and hence races in setting them will not cause malfunction
 546          */
 547
 548         /** Is open/release not implemented by fs? */
 549         unsigned no_open:1;
 550
 551         /** Is fsync not implemented by fs? */
 552         unsigned no_fsync:1;
 553
 554         /** Is fsyncdir not implemented by fs? */
 555         unsigned no_fsyncdir:1;
 556
 557         /** Is flush not implemented by fs? */
 558         unsigned no_flush:1;
 559
 560         /** Is setxattr not implemented by fs? */
 561         unsigned no_setxattr:1;
 562
 563         /** Is getxattr not implemented by fs? */
 564         unsigned no_getxattr:1;
 565
 566         /** Is listxattr not implemented by fs? */
 567         unsigned no_listxattr:1;
 568
 569         /** Is removexattr not implemented by fs? */
 570         unsigned no_removexattr:1;
 571
 572         /** Are posix file locking primitives not implemented by fs? */
 573         unsigned no_lock:1;
 574
 575         /** Is access not implemented by fs? */
 576         unsigned no_access:1;
 577
 578         /** Is create not implemented by fs? */
 579         unsigned no_create:1;
 580
 581         /** Is interrupt not implemented by fs? */
 582         unsigned no_interrupt:1;
 583
 584         /** Is bmap not implemented by fs? */
 585         unsigned no_bmap:1;
 586
 587         /** Is poll not implemented by fs? */
 588         unsigned no_poll:1;
 589
 590         /** Do multi-page cached writes */
 591         unsigned big_writes:1;
 592
 593         /** Don't apply umask to creation modes */
 594         unsigned dont_mask:1;
 595
 596         /** Are BSD file locking primitives not implemented by fs? */
 597         unsigned no_flock:1;
 598
 599         /** Is fallocate not implemented by fs? */
 600         unsigned no_fallocate:1;
 601
 602         /** Is rename with flags implemented by fs? */
 603         unsigned no_rename2:1;
 604
 605         /** Use enhanced/automatic page cache invalidation. */
 606         unsigned auto_inval_data:1;
 607
 608         /** Does the filesystem support readdirplus? */
 609         unsigned do_readdirplus:1;
 610
 611         /** Does the filesystem want adaptive readdirplus? */
 612         unsigned readdirplus_auto:1;
 613
 614         /** Does the filesystem support asynchronous direct-IO submission? */
 615         unsigned async_dio:1;
 616
 617         /** Is lseek not implemented by fs? */
 618         unsigned no_lseek:1;
 619
 620         /** The number of requests waiting for completion */
 621         atomic_t num_waiting;
 622
 623         /** Negotiated minor version */
 624         unsigned minor;
 625
 626         /** Backing dev info */
 627         struct backing_dev_info bdi;
 628
 629         /** Entry on the fuse_conn_list */
 630         struct list_head entry;
 631
 632         /** Device ID from super block */
 633         dev_t dev;
 634
 635         /** Dentries in the control filesystem */
 636         struct dentry *ctl_dentry[FUSE_CTL_NUM_DENTRIES];
 637
 638         /** number of dentries used in the above array */
 639         int ctl_ndents;
 640
 641         /** Key for lock owner ID scrambling */
 642         u32 scramble_key[4];
 643
 644         /** Reserved request for the DESTROY message */
 645         struct fuse_req *destroy_req;
 646
 647         /** Version counter for attribute changes */
 648         u64 attr_version;
 649
 650         /** Called on final put */
 651         void (*release)(struct fuse_conn *);
 652
 653         /** Super block for this connection. */
 654         struct super_block *sb;
 655
 656         /** Read/write semaphore to hold when accessing sb. */
 657         struct rw_semaphore killsb;
 658
 659         /** List of device instances belonging to this connection */
 660         struct list_head devices;
 661 };
 662
 663 static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
 664 {
 665         return sb->s_fs_info;
 666 }
 667
 668 static inline struct fuse_conn *get_fuse_conn(struct inode *inode)
 669 {
 670         return get_fuse_conn_super(inode->i_sb);
 671 }
 672
 673 static inline struct fuse_inode *get_fuse_inode(struct inode *inode)
 674 {
 675         return container_of(inode, struct fuse_inode, inode);
 676 }
 677
 678 static inline u64 get_node_id(struct inode *inode)
 679 {
 680         return get_fuse_inode(inode)->nodeid;
 681 }
 682
 683 /** Device operations */
 684 extern const struct file_operations fuse_dev_operations;
 685
 686 extern const struct dentry_operations fuse_dentry_operations;
 687
 688 /**
 689  * Inode to nodeid comparison.
 690  */
 691 int fuse_inode_eq(struct inode *inode, void *_nodeidp);
 692
 693 /**
 694  * Get a filled in inode
 695  */
 696 struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
 697                         int generation, struct fuse_attr *attr,
 698                         u64 attr_valid, u64 attr_version);
 699
 700 int fuse_lookup_name(struct super_block *sb, u64 nodeid, struct qstr *name,
 701                      struct fuse_entry_out *outarg, struct inode **inode);
 702
 703 /**
 704  * Send FORGET command
 705  */
 706 void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget,
 707                        u64 nodeid, u64 nlookup);
 708
 709 struct fuse_forget_link *fuse_alloc_forget(void);
 710
 711 /* Used by READDIRPLUS */
 712 void fuse_force_forget(struct file *file, u64 nodeid);
 713
 714 /**
 715  * Initialize READ or READDIR request
 716  */
 717 void fuse_read_fill(struct fuse_req *req, struct file *file,
 718                     loff_t pos, size_t count, int opcode);
 719
 720 /**
 721  * Send OPEN or OPENDIR request
 722  */
 723 int fuse_open_common(struct inode *inode, struct file *file, bool isdir);
 724
 725 struct fuse_file *fuse_file_alloc(struct fuse_conn *fc);
 726 struct fuse_file *fuse_file_get(struct fuse_file *ff);
 727 void fuse_file_free(struct fuse_file *ff);
 728 void fuse_finish_open(struct inode *inode, struct file *file);
 729
 730 void fuse_sync_release(struct fuse_file *ff, int flags);
 731
 732 /**
 733  * Send RELEASE or RELEASEDIR request
 734  */
 735 void fuse_release_common(struct file *file, int opcode);
 736
 737 /**
 738  * Send FSYNC or FSYNCDIR request
 739  */
 740 int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
 741                       int datasync, int isdir);
 742
 743 /**
 744  * Notify poll wakeup
 745  */
 746 int fuse_notify_poll_wakeup(struct fuse_conn *fc,
 747                             struct fuse_notify_poll_wakeup_out *outarg);
 748
 749 /**
 750  * Initialize file operations on a regular file
 751  */
 752 void fuse_init_file_inode(struct inode *inode);
 753
 754 /**
 755  * Initialize inode operations on regular files and special files
 756  */
 757 void fuse_init_common(struct inode *inode);
 758
 759 /**
 760  * Initialize inode and file operations on a directory
 761  */
 762 void fuse_init_dir(struct inode *inode);
 763
 764 /**
 765  * Initialize inode operations on a symlink
 766  */
 767 void fuse_init_symlink(struct inode *inode);
 768
 769 /**
 770  * Change attributes of an inode
 771  */
 772 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
 773                             u64 attr_valid, u64 attr_version);
 774
 775 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
 776                                    u64 attr_valid);
 777
 778 /**
 779  * Initialize the client device
 780  */
 781 int fuse_dev_init(void);
 782
 783 /**
 784  * Cleanup the client device
 785  */
 786 void fuse_dev_cleanup(void);
 787
 788 int fuse_ctl_init(void);
 789 void __exit fuse_ctl_cleanup(void);
 790
 791 /**
 792  * Allocate a request
 793  */
 794 struct fuse_req *fuse_request_alloc(unsigned npages);
 795
 796 struct fuse_req *fuse_request_alloc_nofs(unsigned npages);
 797
 798 /**
 799  * Free a request
 800  */
 801 void fuse_request_free(struct fuse_req *req);
 802
 803 /**
 804  * Get a request, may fail with -ENOMEM,
 805  * caller should specify # elements in req->pages[] explicitly
 806  */
 807 struct fuse_req *fuse_get_req(struct fuse_conn *fc, unsigned npages);
 808 struct fuse_req *fuse_get_req_for_background(struct fuse_conn *fc,
 809                                              unsigned npages);
 810
 811 /*
 812  * Increment reference count on request
 813  */
 814 void __fuse_get_request(struct fuse_req *req);
 815
 816 /**
 817  * Gets a requests for a file operation, always succeeds
 818  */
 819 struct fuse_req *fuse_get_req_nofail_nopages(struct fuse_conn *fc,
 820                                              struct file *file);
 821
 822 /**
 823  * Decrement reference count of a request.  If count goes to zero free
 824  * the request.
 825  */
 826 void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req);
 827
 828 /**
 829  * Send a request (synchronous)
 830  */
 831 void fuse_request_send(struct fuse_conn *fc, struct fuse_req *req);
 832
 833 /**
 834  * Simple request sending that does request allocation and freeing
 835  */
 836 ssize_t fuse_simple_request(struct fuse_conn *fc, struct fuse_args *args);
 837
 838 /**
 839  * Send a request in the background
 840  */
 841 void fuse_request_send_background(struct fuse_conn *fc, struct fuse_req *req);
 842
 843 void fuse_request_send_background_locked(struct fuse_conn *fc,
 844                                          struct fuse_req *req);
 845
 846 /* Abort all requests */
 847 void fuse_abort_conn(struct fuse_conn *fc);
 848
 849 /**
 850  * Invalidate inode attributes
 851  */
 852 void fuse_invalidate_attr(struct inode *inode);
 853
 854 void fuse_invalidate_entry_cache(struct dentry *entry);
 855
 856 void fuse_invalidate_atime(struct inode *inode);
 857
 858 /**
 859  * Acquire reference to fuse_conn
 860  */
 861 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc);
 862
 863 /**
 864  * Initialize fuse_conn
 865  */
 866 void fuse_conn_init(struct fuse_conn *fc);
 867
 868 /**
 869  * Release reference to fuse_conn
 870  */
 871 void fuse_conn_put(struct fuse_conn *fc);
 872
 873 struct fuse_dev *fuse_dev_alloc(struct fuse_conn *fc);
 874 void fuse_dev_free(struct fuse_dev *fud);
 875
 876 /**
 877  * Add connection to control filesystem
 878  */
 879 int fuse_ctl_add_conn(struct fuse_conn *fc);
 880
 881 /**
 882  * Remove connection from control filesystem
 883  */
 884 void fuse_ctl_remove_conn(struct fuse_conn *fc);
 885
 886 /**
 887  * Is file type valid?
 888  */
 889 int fuse_valid_type(int m);
 890
 891 /**
 892  * Is current process allowed to perform filesystem operation?
 893  */
 894 int fuse_allow_current_process(struct fuse_conn *fc);
 895
 896 u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id);
 897
 898 int fuse_update_attributes(struct inode *inode, struct kstat *stat,
 899                            struct file *file, bool *refreshed);
 900
 901 void fuse_flush_writepages(struct inode *inode);
 902
 903 void fuse_set_nowrite(struct inode *inode);
 904 void fuse_release_nowrite(struct inode *inode);
 905
 906 u64 fuse_get_attr_version(struct fuse_conn *fc);
 907
 908 /**
 909  * File-system tells the kernel to invalidate cache for the given node id.
 910  */
 911 int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
 912                              loff_t offset, loff_t len);
 913
 914 /**
 915  * File-system tells the kernel to invalidate parent attributes and
 916  * the dentry matching parent/name.
 917  *
 918  * If the child_nodeid is non-zero and:
 919  *    - matches the inode number for the dentry matching parent/name,
 920  *    - is not a mount point
 921  *    - is a file or oan empty directory
 922  * then the dentry is unhashed (d_delete()).
 923  */
 924 int fuse_reverse_inval_entry(struct super_block *sb, u64 parent_nodeid,
 925                              u64 child_nodeid, struct qstr *name);
 926
 927 int fuse_do_open(struct fuse_conn *fc, u64 nodeid, struct file *file,
 928                  bool isdir);
 929
 930 /**
 931  * fuse_direct_io() flags
 932  */
 933
 934 /** If set, it is WRITE; otherwise - READ */
 935 #define FUSE_DIO_WRITE (1 << 0)
 936
 937 /** CUSE pass fuse_direct_io() a file which f_mapping->host is not from FUSE */
 938 #define FUSE_DIO_CUSE  (1 << 1)
 939
 940 ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter,
 941                        loff_t *ppos, int flags);
 942 long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
 943                    unsigned int flags);
 944 long fuse_ioctl_common(struct file *file, unsigned int cmd,
 945                        unsigned long arg, unsigned int flags);
 946 unsigned fuse_file_poll(struct file *file, poll_table *wait);
 947 int fuse_dev_release(struct inode *inode, struct file *file);
 948
 949 bool fuse_write_update_size(struct inode *inode, loff_t pos);
 950
 951 int fuse_flush_times(struct inode *inode, struct fuse_file *ff);
 952 int fuse_write_inode(struct inode *inode, struct writeback_control *wbc);
 953
 954 int fuse_do_setattr(struct inode *inode, struct iattr *attr,
 955                     struct file *file);
 956
 957 void fuse_set_initialized(struct fuse_conn *fc);
 958
 959 #endif /* _FS_FUSE_I_H */