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         bool should_dirty;
 256         int err;
 257         struct kiocb *iocb;
 258         struct file *file;
 259         struct completion *done;
 260 };
 261
 262 #define FUSE_IO_PRIV_SYNC(f) \
 263 {                                       \
 264         .refcnt = { ATOMIC_INIT(1) },   \
 265         .async = 0,                     \
 266         .file = f,                      \
 267 }
 268
 269 /**
 270  * Request flags
 271  *
 272  * FR_ISREPLY:          set if the request has reply
 273  * FR_FORCE:            force sending of the request even if interrupted
 274  * FR_BACKGROUND:       request is sent in the background
 275  * FR_WAITING:          request is counted as "waiting"
 276  * FR_ABORTED:          the request was aborted
 277  * FR_INTERRUPTED:      the request has been interrupted
 278  * FR_LOCKED:           data is being copied to/from the request
 279  * FR_PENDING:          request is not yet in userspace
 280  * FR_SENT:             request is in userspace, waiting for an answer
 281  * FR_FINISHED:         request is finished
 282  * FR_PRIVATE:          request is on private list
 283  */
 284 enum fuse_req_flag {
 285         FR_ISREPLY,
 286         FR_FORCE,
 287         FR_BACKGROUND,
 288         FR_WAITING,
 289         FR_ABORTED,
 290         FR_INTERRUPTED,
 291         FR_LOCKED,
 292         FR_PENDING,
 293         FR_SENT,
 294         FR_FINISHED,
 295         FR_PRIVATE,
 296 };
 297
 298 /**
 299  * A request to the client
 300  *
 301  * .waitq.lock protects the following fields:
 302  *   - FR_ABORTED
 303  *   - FR_LOCKED (may also be modified under fc->lock, tested under both)
 304  */
 305 struct fuse_req {
 306         /** This can be on either pending processing or io lists in
 307             fuse_conn */
 308         struct list_head list;
 309
 310         /** Entry on the interrupts list  */
 311         struct list_head intr_entry;
 312
 313         /** refcount */
 314         atomic_t count;
 315
 316         /** Unique ID for the interrupt request */
 317         u64 intr_unique;
 318
 319         /* Request flags, updated with test/set/clear_bit() */
 320         unsigned long flags;
 321
 322         /** The request input */
 323         struct fuse_in in;
 324
 325         /** The request output */
 326         struct fuse_out out;
 327
 328         /** Used to wake up the task waiting for completion of request*/
 329         wait_queue_head_t waitq;
 330
 331         /** Data for asynchronous requests */
 332         union {
 333                 struct {
 334                         struct fuse_release_in in;
 335                         struct inode *inode;
 336                 } release;
 337                 struct fuse_init_in init_in;
 338                 struct fuse_init_out init_out;
 339                 struct cuse_init_in cuse_init_in;
 340                 struct {
 341                         struct fuse_read_in in;
 342                         u64 attr_ver;
 343                 } read;
 344                 struct {
 345                         struct fuse_write_in in;
 346                         struct fuse_write_out out;
 347                         struct fuse_req *next;
 348                 } write;
 349                 struct fuse_notify_retrieve_in retrieve_in;
 350         } misc;
 351
 352         /** page vector */
 353         struct page **pages;
 354
 355         /** page-descriptor vector */
 356         struct fuse_page_desc *page_descs;
 357
 358         /** size of the 'pages' array */
 359         unsigned max_pages;
 360
 361         /** inline page vector */
 362         struct page *inline_pages[FUSE_REQ_INLINE_PAGES];
 363
 364         /** inline page-descriptor vector */
 365         struct fuse_page_desc inline_page_descs[FUSE_REQ_INLINE_PAGES];
 366
 367         /** number of pages in vector */
 368         unsigned num_pages;
 369
 370         /** File used in the request (or NULL) */
 371         struct fuse_file *ff;
 372
 373         /** Inode used in the request or NULL */
 374         struct inode *inode;
 375
 376         /** AIO control block */
 377         struct fuse_io_priv *io;
 378
 379         /** Link on fi->writepages */
 380         struct list_head writepages_entry;
 381
 382         /** Request completion callback */
 383         void (*end)(struct fuse_conn *, struct fuse_req *);
 384
 385         /** Request is stolen from fuse_file->reserved_req */
 386         struct file *stolen_file;
 387 };
 388
 389 struct fuse_iqueue {
 390         /** Connection established */
 391         unsigned connected;
 392
 393         /** Readers of the connection are waiting on this */
 394         wait_queue_head_t waitq;
 395
 396         /** The next unique request id */
 397         u64 reqctr;
 398
 399         /** The list of pending requests */
 400         struct list_head pending;
 401
 402         /** Pending interrupts */
 403         struct list_head interrupts;
 404
 405         /** Queue of pending forgets */
 406         struct fuse_forget_link forget_list_head;
 407         struct fuse_forget_link *forget_list_tail;
 408
 409         /** Batching of FORGET requests (positive indicates FORGET batch) */
 410         int forget_batch;
 411
 412         /** O_ASYNC requests */
 413         struct fasync_struct *fasync;
 414 };
 415
 416 struct fuse_pqueue {
 417         /** Connection established */
 418         unsigned connected;
 419
 420         /** Lock protecting accessess to  members of this structure */
 421         spinlock_t lock;
 422
 423         /** The list of requests being processed */
 424         struct list_head processing;
 425
 426         /** The list of requests under I/O */
 427         struct list_head io;
 428 };
 429
 430 /**
 431  * Fuse device instance
 432  */
 433 struct fuse_dev {
 434         /** Fuse connection for this device */
 435         struct fuse_conn *fc;
 436
 437         /** Processing queue */
 438         struct fuse_pqueue pq;
 439
 440         /** list entry on fc->devices */
 441         struct list_head entry;
 442 };
 443
 444 /**
 445  * A Fuse connection.
 446  *
 447  * This structure is created, when the filesystem is mounted, and is
 448  * destroyed, when the client device is closed and the filesystem is
 449  * unmounted.
 450  */
 451 struct fuse_conn {
 452         /** Lock protecting accessess to  members of this structure */
 453         spinlock_t lock;
 454
 455         /** Refcount */
 456         atomic_t count;
 457
 458         /** Number of fuse_dev's */
 459         atomic_t dev_count;
 460
 461         struct rcu_head rcu;
 462
 463         /** The user id for this mount */
 464         kuid_t user_id;
 465
 466         /** The group id for this mount */
 467         kgid_t group_id;
 468
 469         /** The fuse mount flags for this mount */
 470         unsigned flags;
 471
 472         /** Maximum read size */
 473         unsigned max_read;
 474
 475         /** Maximum write size */
 476         unsigned max_write;
 477
 478         /** Input queue */
 479         struct fuse_iqueue iq;
 480
 481         /** The next unique kernel file handle */
 482         u64 khctr;
 483
 484         /** rbtree of fuse_files waiting for poll events indexed by ph */
 485         struct rb_root polled_files;
 486
 487         /** Maximum number of outstanding background requests */
 488         unsigned max_background;
 489
 490         /** Number of background requests at which congestion starts */
 491         unsigned congestion_threshold;
 492
 493         /** Number of requests currently in the background */
 494         unsigned num_background;
 495
 496         /** Number of background requests currently queued for userspace */
 497         unsigned active_background;
 498
 499         /** The list of background requests set aside for later queuing */
 500         struct list_head bg_queue;
 501
 502         /** Flag indicating that INIT reply has been received. Allocating
 503          * any fuse request will be suspended until the flag is set */
 504         int initialized;
 505
 506         /** Flag indicating if connection is blocked.  This will be
 507             the case before the INIT reply is received, and if there
 508             are too many outstading backgrounds requests */
 509         int blocked;
 510
 511         /** waitq for blocked connection */
 512         wait_queue_head_t blocked_waitq;
 513
 514         /** waitq for reserved requests */
 515         wait_queue_head_t reserved_req_waitq;
 516
 517         /** Connection established, cleared on umount, connection
 518             abort and device release */
 519         unsigned connected;
 520
 521         /** Connection failed (version mismatch).  Cannot race with
 522             setting other bitfields since it is only set once in INIT
 523             reply, before any other request, and never cleared */
 524         unsigned conn_error:1;
 525
 526         /** Connection successful.  Only set in INIT */
 527         unsigned conn_init:1;
 528
 529         /** Do readpages asynchronously?  Only set in INIT */
 530         unsigned async_read:1;
 531
 532         /** Do not send separate SETATTR request before open(O_TRUNC)  */
 533         unsigned atomic_o_trunc:1;
 534
 535         /** Filesystem supports NFS exporting.  Only set in INIT */
 536         unsigned export_support:1;
 537
 538         /** Set if bdi is valid */
 539         unsigned bdi_initialized:1;
 540
 541         /** write-back cache policy (default is write-through) */
 542         unsigned writeback_cache:1;
 543
 544         /*
 545          * The following bitfields are only for optimization purposes
 546          * and hence races in setting them will not cause malfunction
 547          */
 548
 549         /** Is open/release not implemented by fs? */
 550         unsigned no_open:1;
 551
 552         /** Is fsync not implemented by fs? */
 553         unsigned no_fsync:1;
 554
 555         /** Is fsyncdir not implemented by fs? */
 556         unsigned no_fsyncdir:1;
 557
 558         /** Is flush not implemented by fs? */
 559         unsigned no_flush:1;
 560
 561         /** Is setxattr not implemented by fs? */
 562         unsigned no_setxattr:1;
 563
 564         /** Is getxattr not implemented by fs? */
 565         unsigned no_getxattr:1;
 566
 567         /** Is listxattr not implemented by fs? */
 568         unsigned no_listxattr:1;
 569
 570         /** Is removexattr not implemented by fs? */
 571         unsigned no_removexattr:1;
 572
 573         /** Are posix file locking primitives not implemented by fs? */
 574         unsigned no_lock:1;
 575
 576         /** Is access not implemented by fs? */
 577         unsigned no_access:1;
 578
 579         /** Is create not implemented by fs? */
 580         unsigned no_create:1;
 581
 582         /** Is interrupt not implemented by fs? */
 583         unsigned no_interrupt:1;
 584
 585         /** Is bmap not implemented by fs? */
 586         unsigned no_bmap:1;
 587
 588         /** Is poll not implemented by fs? */
 589         unsigned no_poll:1;
 590
 591         /** Do multi-page cached writes */
 592         unsigned big_writes:1;
 593
 594         /** Don't apply umask to creation modes */
 595         unsigned dont_mask:1;
 596
 597         /** Are BSD file locking primitives not implemented by fs? */
 598         unsigned no_flock:1;
 599
 600         /** Is fallocate not implemented by fs? */
 601         unsigned no_fallocate:1;
 602
 603         /** Is rename with flags implemented by fs? */
 604         unsigned no_rename2:1;
 605
 606         /** Use enhanced/automatic page cache invalidation. */
 607         unsigned auto_inval_data:1;
 608
 609         /** Does the filesystem support readdirplus? */
 610         unsigned do_readdirplus:1;
 611
 612         /** Does the filesystem want adaptive readdirplus? */
 613         unsigned readdirplus_auto:1;
 614
 615         /** Does the filesystem support asynchronous direct-IO submission? */
 616         unsigned async_dio:1;
 617
 618         /** The number of requests waiting for completion */
 619         atomic_t num_waiting;
 620
 621         /** Negotiated minor version */
 622         unsigned minor;
 623
 624         /** Backing dev info */
 625         struct backing_dev_info bdi;
 626
 627         /** Entry on the fuse_conn_list */
 628         struct list_head entry;
 629
 630         /** Device ID from super block */
 631         dev_t dev;
 632
 633         /** Dentries in the control filesystem */
 634         struct dentry *ctl_dentry[FUSE_CTL_NUM_DENTRIES];
 635
 636         /** number of dentries used in the above array */
 637         int ctl_ndents;
 638
 639         /** Key for lock owner ID scrambling */
 640         u32 scramble_key[4];
 641
 642         /** Reserved request for the DESTROY message */
 643         struct fuse_req *destroy_req;
 644
 645         /** Version counter for attribute changes */
 646         u64 attr_version;
 647
 648         /** Called on final put */
 649         void (*release)(struct fuse_conn *);
 650
 651         /** Super block for this connection. */
 652         struct super_block *sb;
 653
 654         /** Read/write semaphore to hold when accessing sb. */
 655         struct rw_semaphore killsb;
 656
 657         /** List of device instances belonging to this connection */
 658         struct list_head devices;
 659 };
 660
 661 static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
 662 {
 663         return sb->s_fs_info;
 664 }
 665
 666 static inline struct fuse_conn *get_fuse_conn(struct inode *inode)
 667 {
 668         return get_fuse_conn_super(inode->i_sb);
 669 }
 670
 671 static inline struct fuse_inode *get_fuse_inode(struct inode *inode)
 672 {
 673         return container_of(inode, struct fuse_inode, inode);
 674 }
 675
 676 static inline u64 get_node_id(struct inode *inode)
 677 {
 678         return get_fuse_inode(inode)->nodeid;
 679 }
 680
 681 /** Device operations */
 682 extern const struct file_operations fuse_dev_operations;
 683
 684 extern const struct dentry_operations fuse_dentry_operations;
 685
 686 /**
 687  * Inode to nodeid comparison.
 688  */
 689 int fuse_inode_eq(struct inode *inode, void *_nodeidp);
 690
 691 /**
 692  * Get a filled in inode
 693  */
 694 struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
 695                         int generation, struct fuse_attr *attr,
 696                         u64 attr_valid, u64 attr_version);
 697
 698 int fuse_lookup_name(struct super_block *sb, u64 nodeid, struct qstr *name,
 699                      struct fuse_entry_out *outarg, struct inode **inode);
 700
 701 /**
 702  * Send FORGET command
 703  */
 704 void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget,
 705                        u64 nodeid, u64 nlookup);
 706
 707 struct fuse_forget_link *fuse_alloc_forget(void);
 708
 709 /* Used by READDIRPLUS */
 710 void fuse_force_forget(struct file *file, u64 nodeid);
 711
 712 /**
 713  * Initialize READ or READDIR request
 714  */
 715 void fuse_read_fill(struct fuse_req *req, struct file *file,
 716                     loff_t pos, size_t count, int opcode);
 717
 718 /**
 719  * Send OPEN or OPENDIR request
 720  */
 721 int fuse_open_common(struct inode *inode, struct file *file, bool isdir);
 722
 723 struct fuse_file *fuse_file_alloc(struct fuse_conn *fc);
 724 struct fuse_file *fuse_file_get(struct fuse_file *ff);
 725 void fuse_file_free(struct fuse_file *ff);
 726 void fuse_finish_open(struct inode *inode, struct file *file);
 727
 728 void fuse_sync_release(struct fuse_file *ff, int flags);
 729
 730 /**
 731  * Send RELEASE or RELEASEDIR request
 732  */
 733 void fuse_release_common(struct file *file, int opcode);
 734
 735 /**
 736  * Send FSYNC or FSYNCDIR request
 737  */
 738 int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
 739                       int datasync, int isdir);
 740
 741 /**
 742  * Notify poll wakeup
 743  */
 744 int fuse_notify_poll_wakeup(struct fuse_conn *fc,
 745                             struct fuse_notify_poll_wakeup_out *outarg);
 746
 747 /**
 748  * Initialize file operations on a regular file
 749  */
 750 void fuse_init_file_inode(struct inode *inode);
 751
 752 /**
 753  * Initialize inode operations on regular files and special files
 754  */
 755 void fuse_init_common(struct inode *inode);
 756
 757 /**
 758  * Initialize inode and file operations on a directory
 759  */
 760 void fuse_init_dir(struct inode *inode);
 761
 762 /**
 763  * Initialize inode operations on a symlink
 764  */
 765 void fuse_init_symlink(struct inode *inode);
 766
 767 /**
 768  * Change attributes of an inode
 769  */
 770 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
 771                             u64 attr_valid, u64 attr_version);
 772
 773 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
 774                                    u64 attr_valid);
 775
 776 /**
 777  * Initialize the client device
 778  */
 779 int fuse_dev_init(void);
 780
 781 /**
 782  * Cleanup the client device
 783  */
 784 void fuse_dev_cleanup(void);
 785
 786 int fuse_ctl_init(void);
 787 void __exit fuse_ctl_cleanup(void);
 788
 789 /**
 790  * Allocate a request
 791  */
 792 struct fuse_req *fuse_request_alloc(unsigned npages);
 793
 794 struct fuse_req *fuse_request_alloc_nofs(unsigned npages);
 795
 796 /**
 797  * Free a request
 798  */
 799 void fuse_request_free(struct fuse_req *req);
 800
 801 /**
 802  * Get a request, may fail with -ENOMEM,
 803  * caller should specify # elements in req->pages[] explicitly
 804  */
 805 struct fuse_req *fuse_get_req(struct fuse_conn *fc, unsigned npages);
 806 struct fuse_req *fuse_get_req_for_background(struct fuse_conn *fc,
 807                                              unsigned npages);
 808
 809 /*
 810  * Increment reference count on request
 811  */
 812 void __fuse_get_request(struct fuse_req *req);
 813
 814 /**
 815  * Gets a requests for a file operation, always succeeds
 816  */
 817 struct fuse_req *fuse_get_req_nofail_nopages(struct fuse_conn *fc,
 818                                              struct file *file);
 819
 820 /**
 821  * Decrement reference count of a request.  If count goes to zero free
 822  * the request.
 823  */
 824 void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req);
 825
 826 /**
 827  * Send a request (synchronous)
 828  */
 829 void fuse_request_send(struct fuse_conn *fc, struct fuse_req *req);
 830
 831 /**
 832  * Simple request sending that does request allocation and freeing
 833  */
 834 ssize_t fuse_simple_request(struct fuse_conn *fc, struct fuse_args *args);
 835
 836 /**
 837  * Send a request in the background
 838  */
 839 void fuse_request_send_background(struct fuse_conn *fc, struct fuse_req *req);
 840
 841 void fuse_request_send_background_locked(struct fuse_conn *fc,
 842                                          struct fuse_req *req);
 843
 844 /* Abort all requests */
 845 void fuse_abort_conn(struct fuse_conn *fc);
 846 void fuse_wait_aborted(struct fuse_conn *fc);
 847
 848 /**
 849  * Invalidate inode attributes
 850  */
 851 void fuse_invalidate_attr(struct inode *inode);
 852
 853 void fuse_invalidate_entry_cache(struct dentry *entry);
 854
 855 void fuse_invalidate_atime(struct inode *inode);
 856
 857 /**
 858  * Acquire reference to fuse_conn
 859  */
 860 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc);
 861
 862 /**
 863  * Initialize fuse_conn
 864  */
 865 void fuse_conn_init(struct fuse_conn *fc);
 866
 867 /**
 868  * Release reference to fuse_conn
 869  */
 870 void fuse_conn_put(struct fuse_conn *fc);
 871
 872 struct fuse_dev *fuse_dev_alloc(struct fuse_conn *fc);
 873 void fuse_dev_free(struct fuse_dev *fud);
 874
 875 /**
 876  * Add connection to control filesystem
 877  */
 878 int fuse_ctl_add_conn(struct fuse_conn *fc);
 879
 880 /**
 881  * Remove connection from control filesystem
 882  */
 883 void fuse_ctl_remove_conn(struct fuse_conn *fc);
 884
 885 /**
 886  * Is file type valid?
 887  */
 888 int fuse_valid_type(int m);
 889
 890 bool fuse_invalid_attr(struct fuse_attr *attr);
 891
 892 /**
 893  * Is current process allowed to perform filesystem operation?
 894  */
 895 int fuse_allow_current_process(struct fuse_conn *fc);
 896
 897 u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id);
 898
 899 int fuse_update_attributes(struct inode *inode, struct kstat *stat,
 900                            struct file *file, bool *refreshed);
 901
 902 void fuse_flush_writepages(struct inode *inode);
 903
 904 void fuse_set_nowrite(struct inode *inode);
 905 void fuse_release_nowrite(struct inode *inode);
 906
 907 u64 fuse_get_attr_version(struct fuse_conn *fc);
 908
 909 /**
 910  * File-system tells the kernel to invalidate cache for the given node id.
 911  */
 912 int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
 913                              loff_t offset, loff_t len);
 914
 915 /**
 916  * File-system tells the kernel to invalidate parent attributes and
 917  * the dentry matching parent/name.
 918  *
 919  * If the child_nodeid is non-zero and:
 920  *    - matches the inode number for the dentry matching parent/name,
 921  *    - is not a mount point
 922  *    - is a file or oan empty directory
 923  * then the dentry is unhashed (d_delete()).
 924  */
 925 int fuse_reverse_inval_entry(struct super_block *sb, u64 parent_nodeid,
 926                              u64 child_nodeid, struct qstr *name);
 927
 928 int fuse_do_open(struct fuse_conn *fc, u64 nodeid, struct file *file,
 929                  bool isdir);
 930
 931 /**
 932  * fuse_direct_io() flags
 933  */
 934
 935 /** If set, it is WRITE; otherwise - READ */
 936 #define FUSE_DIO_WRITE (1 << 0)
 937
 938 /** CUSE pass fuse_direct_io() a file which f_mapping->host is not from FUSE */
 939 #define FUSE_DIO_CUSE  (1 << 1)
 940
 941 ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter,
 942                        loff_t *ppos, int flags);
 943 long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
 944                    unsigned int flags);
 945 long fuse_ioctl_common(struct file *file, unsigned int cmd,
 946                        unsigned long arg, unsigned int flags);
 947 unsigned fuse_file_poll(struct file *file, poll_table *wait);
 948 int fuse_dev_release(struct inode *inode, struct file *file);
 949
 950 bool fuse_write_update_size(struct inode *inode, loff_t pos);
 951
 952 int fuse_flush_times(struct inode *inode, struct fuse_file *ff);
 953 int fuse_write_inode(struct inode *inode, struct writeback_control *wbc);
 954
 955 int fuse_do_setattr(struct inode *inode, struct iattr *attr,
 956                     struct file *file);
 957
 958 void fuse_set_initialized(struct fuse_conn *fc);
 959
 960 #endif /* _FS_FUSE_I_H */