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         /** Lock for serializing lookup and readdir for back compatibility*/
 115         struct mutex mutex;
 116 };
 117
 118 /** FUSE inode state bits */
 119 enum {
 120         /** Advise readdirplus  */
 121         FUSE_I_ADVISE_RDPLUS,
 122         /** Initialized with readdirplus */
 123         FUSE_I_INIT_RDPLUS,
 124         /** An operation changing file size is in progress  */
 125         FUSE_I_SIZE_UNSTABLE,
 126 };
 127
 128 struct fuse_conn;
 129
 130 /** FUSE specific file data */
 131 struct fuse_file {
 132         /** Fuse connection for this file */
 133         struct fuse_conn *fc;
 134
 135         /** Request reserved for flush and release */
 136         struct fuse_req *reserved_req;
 137
 138         /** Kernel file handle guaranteed to be unique */
 139         u64 kh;
 140
 141         /** File handle used by userspace */
 142         u64 fh;
 143
 144         /** Node id of this file */
 145         u64 nodeid;
 146
 147         /** Refcount */
 148         atomic_t count;
 149
 150         /** FOPEN_* flags returned by open */
 151         u32 open_flags;
 152
 153         /** Entry on inode's write_files list */
 154         struct list_head write_entry;
 155
 156         /** RB node to be linked on fuse_conn->polled_files */
 157         struct rb_node polled_node;
 158
 159         /** Wait queue head for poll */
 160         wait_queue_head_t poll_wait;
 161
 162         /** Has flock been performed on this file? */
 163         bool flock:1;
 164 };
 165
 166 /** One input argument of a request */
 167 struct fuse_in_arg {
 168         unsigned size;
 169         const void *value;
 170 };
 171
 172 /** The request input */
 173 struct fuse_in {
 174         /** The request header */
 175         struct fuse_in_header h;
 176
 177         /** True if the data for the last argument is in req->pages */
 178         unsigned argpages:1;
 179
 180         /** Number of arguments */
 181         unsigned numargs;
 182
 183         /** Array of arguments */
 184         struct fuse_in_arg args[3];
 185 };
 186
 187 /** One output argument of a request */
 188 struct fuse_arg {
 189         unsigned size;
 190         void *value;
 191 };
 192
 193 /** The request output */
 194 struct fuse_out {
 195         /** Header returned from userspace */
 196         struct fuse_out_header h;
 197
 198         /*
 199          * The following bitfields are not changed during the request
 200          * processing
 201          */
 202
 203         /** Last argument is variable length (can be shorter than
 204             arg->size) */
 205         unsigned argvar:1;
 206
 207         /** Last argument is a list of pages to copy data to */
 208         unsigned argpages:1;
 209
 210         /** Zero partially or not copied pages */
 211         unsigned page_zeroing:1;
 212
 213         /** Pages may be replaced with new ones */
 214         unsigned page_replace:1;
 215
 216         /** Number or arguments */
 217         unsigned numargs;
 218
 219         /** Array of arguments */
 220         struct fuse_arg args[2];
 221 };
 222
 223 /** FUSE page descriptor */
 224 struct fuse_page_desc {
 225         unsigned int length;
 226         unsigned int offset;
 227 };
 228
 229 struct fuse_args {
 230         struct {
 231                 struct {
 232                         uint32_t opcode;
 233                         uint64_t nodeid;
 234                 } h;
 235                 unsigned numargs;
 236                 struct fuse_in_arg args[3];
 237
 238         } in;
 239         struct {
 240                 unsigned argvar:1;
 241                 unsigned numargs;
 242                 struct fuse_arg args[2];
 243         } out;
 244 };
 245
 246 #define FUSE_ARGS(args) struct fuse_args args = {}
 247
 248 /** The request IO state (for asynchronous processing) */
 249 struct fuse_io_priv {
 250         struct kref refcnt;
 251         int async;
 252         spinlock_t lock;
 253         unsigned reqs;
 254         ssize_t bytes;
 255         size_t size;
 256         __u64 offset;
 257         bool write;
 258         int err;
 259         struct kiocb *iocb;
 260         struct file *file;
 261         struct completion *done;
 262         bool blocking;
 263 };
 264
 265 #define FUSE_IO_PRIV_SYNC(f) \
 266 {                                       \
 267         .refcnt = { ATOMIC_INIT(1) },   \
 268         .async = 0,                     \
 269         .file = f,                      \
 270 }
 271
 272 /**
 273  * Request flags
 274  *
 275  * FR_ISREPLY:          set if the request has reply
 276  * FR_FORCE:            force sending of the request even if interrupted
 277  * FR_BACKGROUND:       request is sent in the background
 278  * FR_WAITING:          request is counted as "waiting"
 279  * FR_ABORTED:          the request was aborted
 280  * FR_INTERRUPTED:      the request has been interrupted
 281  * FR_LOCKED:           data is being copied to/from the request
 282  * FR_PENDING:          request is not yet in userspace
 283  * FR_SENT:             request is in userspace, waiting for an answer
 284  * FR_FINISHED:         request is finished
 285  * FR_PRIVATE:          request is on private list
 286  */
 287 enum fuse_req_flag {
 288         FR_ISREPLY,
 289         FR_FORCE,
 290         FR_BACKGROUND,
 291         FR_WAITING,
 292         FR_ABORTED,
 293         FR_INTERRUPTED,
 294         FR_LOCKED,
 295         FR_PENDING,
 296         FR_SENT,
 297         FR_FINISHED,
 298         FR_PRIVATE,
 299 };
 300
 301 /**
 302  * A request to the client
 303  *
 304  * .waitq.lock protects the following fields:
 305  *   - FR_ABORTED
 306  *   - FR_LOCKED (may also be modified under fc->lock, tested under both)
 307  */
 308 struct fuse_req {
 309         /** This can be on either pending processing or io lists in
 310             fuse_conn */
 311         struct list_head list;
 312
 313         /** Entry on the interrupts list  */
 314         struct list_head intr_entry;
 315
 316         /** refcount */
 317         atomic_t count;
 318
 319         /** Unique ID for the interrupt request */
 320         u64 intr_unique;
 321
 322         /* Request flags, updated with test/set/clear_bit() */
 323         unsigned long flags;
 324
 325         /** The request input */
 326         struct fuse_in in;
 327
 328         /** The request output */
 329         struct fuse_out out;
 330
 331         /** Used to wake up the task waiting for completion of request*/
 332         wait_queue_head_t waitq;
 333
 334         /** Data for asynchronous requests */
 335         union {
 336                 struct {
 337                         struct fuse_release_in in;
 338                         struct inode *inode;
 339                 } release;
 340                 struct fuse_init_in init_in;
 341                 struct fuse_init_out init_out;
 342                 struct cuse_init_in cuse_init_in;
 343                 struct {
 344                         struct fuse_read_in in;
 345                         u64 attr_ver;
 346                 } read;
 347                 struct {
 348                         struct fuse_write_in in;
 349                         struct fuse_write_out out;
 350                         struct fuse_req *next;
 351                 } write;
 352                 struct fuse_notify_retrieve_in retrieve_in;
 353         } misc;
 354
 355         /** page vector */
 356         struct page **pages;
 357
 358         /** page-descriptor vector */
 359         struct fuse_page_desc *page_descs;
 360
 361         /** size of the 'pages' array */
 362         unsigned max_pages;
 363
 364         /** inline page vector */
 365         struct page *inline_pages[FUSE_REQ_INLINE_PAGES];
 366
 367         /** inline page-descriptor vector */
 368         struct fuse_page_desc inline_page_descs[FUSE_REQ_INLINE_PAGES];
 369
 370         /** number of pages in vector */
 371         unsigned num_pages;
 372
 373         /** File used in the request (or NULL) */
 374         struct fuse_file *ff;
 375
 376         /** Inode used in the request or NULL */
 377         struct inode *inode;
 378
 379         /** AIO control block */
 380         struct fuse_io_priv *io;
 381
 382         /** Link on fi->writepages */
 383         struct list_head writepages_entry;
 384
 385         /** Request completion callback */
 386         void (*end)(struct fuse_conn *, struct fuse_req *);
 387
 388         /** Request is stolen from fuse_file->reserved_req */
 389         struct file *stolen_file;
 390 };
 391
 392 struct fuse_iqueue {
 393         /** Connection established */
 394         unsigned connected;
 395
 396         /** Readers of the connection are waiting on this */
 397         wait_queue_head_t waitq;
 398
 399         /** The next unique request id */
 400         u64 reqctr;
 401
 402         /** The list of pending requests */
 403         struct list_head pending;
 404
 405         /** Pending interrupts */
 406         struct list_head interrupts;
 407
 408         /** Queue of pending forgets */
 409         struct fuse_forget_link forget_list_head;
 410         struct fuse_forget_link *forget_list_tail;
 411
 412         /** Batching of FORGET requests (positive indicates FORGET batch) */
 413         int forget_batch;
 414
 415         /** O_ASYNC requests */
 416         struct fasync_struct *fasync;
 417 };
 418
 419 struct fuse_pqueue {
 420         /** Connection established */
 421         unsigned connected;
 422
 423         /** Lock protecting accessess to  members of this structure */
 424         spinlock_t lock;
 425
 426         /** The list of requests being processed */
 427         struct list_head processing;
 428
 429         /** The list of requests under I/O */
 430         struct list_head io;
 431 };
 432
 433 /**
 434  * Fuse device instance
 435  */
 436 struct fuse_dev {
 437         /** Fuse connection for this device */
 438         struct fuse_conn *fc;
 439
 440         /** Processing queue */
 441         struct fuse_pqueue pq;
 442
 443         /** list entry on fc->devices */
 444         struct list_head entry;
 445 };
 446
 447 /**
 448  * A Fuse connection.
 449  *
 450  * This structure is created, when the filesystem is mounted, and is
 451  * destroyed, when the client device is closed and the filesystem is
 452  * unmounted.
 453  */
 454 struct fuse_conn {
 455         /** Lock protecting accessess to  members of this structure */
 456         spinlock_t lock;
 457
 458         /** Refcount */
 459         atomic_t count;
 460
 461         /** Number of fuse_dev's */
 462         atomic_t dev_count;
 463
 464         struct rcu_head rcu;
 465
 466         /** The user id for this mount */
 467         kuid_t user_id;
 468
 469         /** The group id for this mount */
 470         kgid_t group_id;
 471
 472         /** The fuse mount flags for this mount */
 473         unsigned flags;
 474
 475         /** Maximum read size */
 476         unsigned max_read;
 477
 478         /** Maximum write size */
 479         unsigned max_write;
 480
 481         /** Input queue */
 482         struct fuse_iqueue iq;
 483
 484         /** The next unique kernel file handle */
 485         u64 khctr;
 486
 487         /** rbtree of fuse_files waiting for poll events indexed by ph */
 488         struct rb_root polled_files;
 489
 490         /** Maximum number of outstanding background requests */
 491         unsigned max_background;
 492
 493         /** Number of background requests at which congestion starts */
 494         unsigned congestion_threshold;
 495
 496         /** Number of requests currently in the background */
 497         unsigned num_background;
 498
 499         /** Number of background requests currently queued for userspace */
 500         unsigned active_background;
 501
 502         /** The list of background requests set aside for later queuing */
 503         struct list_head bg_queue;
 504
 505         /** Flag indicating that INIT reply has been received. Allocating
 506          * any fuse request will be suspended until the flag is set */
 507         int initialized;
 508
 509         /** Flag indicating if connection is blocked.  This will be
 510             the case before the INIT reply is received, and if there
 511             are too many outstading backgrounds requests */
 512         int blocked;
 513
 514         /** waitq for blocked connection */
 515         wait_queue_head_t blocked_waitq;
 516
 517         /** waitq for reserved requests */
 518         wait_queue_head_t reserved_req_waitq;
 519
 520         /** Connection established, cleared on umount, connection
 521             abort and device release */
 522         unsigned connected;
 523
 524         /** Connection failed (version mismatch).  Cannot race with
 525             setting other bitfields since it is only set once in INIT
 526             reply, before any other request, and never cleared */
 527         unsigned conn_error:1;
 528
 529         /** Connection successful.  Only set in INIT */
 530         unsigned conn_init:1;
 531
 532         /** Do readpages asynchronously?  Only set in INIT */
 533         unsigned async_read:1;
 534
 535         /** Do not send separate SETATTR request before open(O_TRUNC)  */
 536         unsigned atomic_o_trunc:1;
 537
 538         /** Filesystem supports NFS exporting.  Only set in INIT */
 539         unsigned export_support:1;
 540
 541         /** Set if bdi is valid */
 542         unsigned bdi_initialized:1;
 543
 544         /** write-back cache policy (default is write-through) */
 545         unsigned writeback_cache:1;
 546
 547         /** allow parallel lookups and readdir (default is serialized) */
 548         unsigned parallel_dirops:1;
 549
 550         /*
 551          * The following bitfields are only for optimization purposes
 552          * and hence races in setting them will not cause malfunction
 553          */
 554
 555         /** Is open/release not implemented by fs? */
 556         unsigned no_open:1;
 557
 558         /** Is fsync not implemented by fs? */
 559         unsigned no_fsync:1;
 560
 561         /** Is fsyncdir not implemented by fs? */
 562         unsigned no_fsyncdir:1;
 563
 564         /** Is flush not implemented by fs? */
 565         unsigned no_flush:1;
 566
 567         /** Is setxattr not implemented by fs? */
 568         unsigned no_setxattr:1;
 569
 570         /** Is getxattr not implemented by fs? */
 571         unsigned no_getxattr:1;
 572
 573         /** Is listxattr not implemented by fs? */
 574         unsigned no_listxattr:1;
 575
 576         /** Is removexattr not implemented by fs? */
 577         unsigned no_removexattr:1;
 578
 579         /** Are posix file locking primitives not implemented by fs? */
 580         unsigned no_lock:1;
 581
 582         /** Is access not implemented by fs? */
 583         unsigned no_access:1;
 584
 585         /** Is create not implemented by fs? */
 586         unsigned no_create:1;
 587
 588         /** Is interrupt not implemented by fs? */
 589         unsigned no_interrupt:1;
 590
 591         /** Is bmap not implemented by fs? */
 592         unsigned no_bmap:1;
 593
 594         /** Is poll not implemented by fs? */
 595         unsigned no_poll:1;
 596
 597         /** Do multi-page cached writes */
 598         unsigned big_writes:1;
 599
 600         /** Don't apply umask to creation modes */
 601         unsigned dont_mask:1;
 602
 603         /** Are BSD file locking primitives not implemented by fs? */
 604         unsigned no_flock:1;
 605
 606         /** Is fallocate not implemented by fs? */
 607         unsigned no_fallocate:1;
 608
 609         /** Is rename with flags implemented by fs? */
 610         unsigned no_rename2:1;
 611
 612         /** Use enhanced/automatic page cache invalidation. */
 613         unsigned auto_inval_data:1;
 614
 615         /** Does the filesystem support readdirplus? */
 616         unsigned do_readdirplus:1;
 617
 618         /** Does the filesystem want adaptive readdirplus? */
 619         unsigned readdirplus_auto:1;
 620
 621         /** Does the filesystem support asynchronous direct-IO submission? */
 622         unsigned async_dio:1;
 623
 624         /** Is lseek not implemented by fs? */
 625         unsigned no_lseek:1;
 626
 627         /** The number of requests waiting for completion */
 628         atomic_t num_waiting;
 629
 630         /** Negotiated minor version */
 631         unsigned minor;
 632
 633         /** Backing dev info */
 634         struct backing_dev_info bdi;
 635
 636         /** Entry on the fuse_conn_list */
 637         struct list_head entry;
 638
 639         /** Device ID from super block */
 640         dev_t dev;
 641
 642         /** Dentries in the control filesystem */
 643         struct dentry *ctl_dentry[FUSE_CTL_NUM_DENTRIES];
 644
 645         /** number of dentries used in the above array */
 646         int ctl_ndents;
 647
 648         /** Key for lock owner ID scrambling */
 649         u32 scramble_key[4];
 650
 651         /** Reserved request for the DESTROY message */
 652         struct fuse_req *destroy_req;
 653
 654         /** Version counter for attribute changes */
 655         u64 attr_version;
 656
 657         /** Called on final put */
 658         void (*release)(struct fuse_conn *);
 659
 660         /** Super block for this connection. */
 661         struct super_block *sb;
 662
 663         /** Read/write semaphore to hold when accessing sb. */
 664         struct rw_semaphore killsb;
 665
 666         /** List of device instances belonging to this connection */
 667         struct list_head devices;
 668 };
 669
 670 static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
 671 {
 672         return sb->s_fs_info;
 673 }
 674
 675 static inline struct fuse_conn *get_fuse_conn(struct inode *inode)
 676 {
 677         return get_fuse_conn_super(inode->i_sb);
 678 }
 679
 680 static inline struct fuse_inode *get_fuse_inode(struct inode *inode)
 681 {
 682         return container_of(inode, struct fuse_inode, inode);
 683 }
 684
 685 static inline u64 get_node_id(struct inode *inode)
 686 {
 687         return get_fuse_inode(inode)->nodeid;
 688 }
 689
 690 /** Device operations */
 691 extern const struct file_operations fuse_dev_operations;
 692
 693 extern const struct dentry_operations fuse_dentry_operations;
 694
 695 /**
 696  * Inode to nodeid comparison.
 697  */
 698 int fuse_inode_eq(struct inode *inode, void *_nodeidp);
 699
 700 /**
 701  * Get a filled in inode
 702  */
 703 struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
 704                         int generation, struct fuse_attr *attr,
 705                         u64 attr_valid, u64 attr_version);
 706
 707 int fuse_lookup_name(struct super_block *sb, u64 nodeid, const struct qstr *name,
 708                      struct fuse_entry_out *outarg, struct inode **inode);
 709
 710 /**
 711  * Send FORGET command
 712  */
 713 void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget,
 714                        u64 nodeid, u64 nlookup);
 715
 716 struct fuse_forget_link *fuse_alloc_forget(void);
 717
 718 /* Used by READDIRPLUS */
 719 void fuse_force_forget(struct file *file, u64 nodeid);
 720
 721 /**
 722  * Initialize READ or READDIR request
 723  */
 724 void fuse_read_fill(struct fuse_req *req, struct file *file,
 725                     loff_t pos, size_t count, int opcode);
 726
 727 /**
 728  * Send OPEN or OPENDIR request
 729  */
 730 int fuse_open_common(struct inode *inode, struct file *file, bool isdir);
 731
 732 struct fuse_file *fuse_file_alloc(struct fuse_conn *fc);
 733 struct fuse_file *fuse_file_get(struct fuse_file *ff);
 734 void fuse_file_free(struct fuse_file *ff);
 735 void fuse_finish_open(struct inode *inode, struct file *file);
 736
 737 void fuse_sync_release(struct fuse_file *ff, int flags);
 738
 739 /**
 740  * Send RELEASE or RELEASEDIR request
 741  */
 742 void fuse_release_common(struct file *file, int opcode);
 743
 744 /**
 745  * Send FSYNC or FSYNCDIR request
 746  */
 747 int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
 748                       int datasync, int isdir);
 749
 750 /**
 751  * Notify poll wakeup
 752  */
 753 int fuse_notify_poll_wakeup(struct fuse_conn *fc,
 754                             struct fuse_notify_poll_wakeup_out *outarg);
 755
 756 /**
 757  * Initialize file operations on a regular file
 758  */
 759 void fuse_init_file_inode(struct inode *inode);
 760
 761 /**
 762  * Initialize inode operations on regular files and special files
 763  */
 764 void fuse_init_common(struct inode *inode);
 765
 766 /**
 767  * Initialize inode and file operations on a directory
 768  */
 769 void fuse_init_dir(struct inode *inode);
 770
 771 /**
 772  * Initialize inode operations on a symlink
 773  */
 774 void fuse_init_symlink(struct inode *inode);
 775
 776 /**
 777  * Change attributes of an inode
 778  */
 779 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
 780                             u64 attr_valid, u64 attr_version);
 781
 782 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
 783                                    u64 attr_valid);
 784
 785 /**
 786  * Initialize the client device
 787  */
 788 int fuse_dev_init(void);
 789
 790 /**
 791  * Cleanup the client device
 792  */
 793 void fuse_dev_cleanup(void);
 794
 795 int fuse_ctl_init(void);
 796 void __exit fuse_ctl_cleanup(void);
 797
 798 /**
 799  * Allocate a request
 800  */
 801 struct fuse_req *fuse_request_alloc(unsigned npages);
 802
 803 struct fuse_req *fuse_request_alloc_nofs(unsigned npages);
 804
 805 /**
 806  * Free a request
 807  */
 808 void fuse_request_free(struct fuse_req *req);
 809
 810 /**
 811  * Get a request, may fail with -ENOMEM,
 812  * caller should specify # elements in req->pages[] explicitly
 813  */
 814 struct fuse_req *fuse_get_req(struct fuse_conn *fc, unsigned npages);
 815 struct fuse_req *fuse_get_req_for_background(struct fuse_conn *fc,
 816                                              unsigned npages);
 817
 818 /*
 819  * Increment reference count on request
 820  */
 821 void __fuse_get_request(struct fuse_req *req);
 822
 823 /**
 824  * Gets a requests for a file operation, always succeeds
 825  */
 826 struct fuse_req *fuse_get_req_nofail_nopages(struct fuse_conn *fc,
 827                                              struct file *file);
 828
 829 /**
 830  * Decrement reference count of a request.  If count goes to zero free
 831  * the request.
 832  */
 833 void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req);
 834
 835 /**
 836  * Send a request (synchronous)
 837  */
 838 void fuse_request_send(struct fuse_conn *fc, struct fuse_req *req);
 839
 840 /**
 841  * Simple request sending that does request allocation and freeing
 842  */
 843 ssize_t fuse_simple_request(struct fuse_conn *fc, struct fuse_args *args);
 844
 845 /**
 846  * Send a request in the background
 847  */
 848 void fuse_request_send_background(struct fuse_conn *fc, struct fuse_req *req);
 849
 850 void fuse_request_send_background_locked(struct fuse_conn *fc,
 851                                          struct fuse_req *req);
 852
 853 /* Abort all requests */
 854 void fuse_abort_conn(struct fuse_conn *fc);
 855
 856 /**
 857  * Invalidate inode attributes
 858  */
 859 void fuse_invalidate_attr(struct inode *inode);
 860
 861 void fuse_invalidate_entry_cache(struct dentry *entry);
 862
 863 void fuse_invalidate_atime(struct inode *inode);
 864
 865 /**
 866  * Acquire reference to fuse_conn
 867  */
 868 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc);
 869
 870 /**
 871  * Initialize fuse_conn
 872  */
 873 void fuse_conn_init(struct fuse_conn *fc);
 874
 875 /**
 876  * Release reference to fuse_conn
 877  */
 878 void fuse_conn_put(struct fuse_conn *fc);
 879
 880 struct fuse_dev *fuse_dev_alloc(struct fuse_conn *fc);
 881 void fuse_dev_free(struct fuse_dev *fud);
 882
 883 /**
 884  * Add connection to control filesystem
 885  */
 886 int fuse_ctl_add_conn(struct fuse_conn *fc);
 887
 888 /**
 889  * Remove connection from control filesystem
 890  */
 891 void fuse_ctl_remove_conn(struct fuse_conn *fc);
 892
 893 /**
 894  * Is file type valid?
 895  */
 896 int fuse_valid_type(int m);
 897
 898 /**
 899  * Is current process allowed to perform filesystem operation?
 900  */
 901 int fuse_allow_current_process(struct fuse_conn *fc);
 902
 903 u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id);
 904
 905 int fuse_update_attributes(struct inode *inode, struct kstat *stat,
 906                            struct file *file, bool *refreshed);
 907
 908 void fuse_flush_writepages(struct inode *inode);
 909
 910 void fuse_set_nowrite(struct inode *inode);
 911 void fuse_release_nowrite(struct inode *inode);
 912
 913 u64 fuse_get_attr_version(struct fuse_conn *fc);
 914
 915 /**
 916  * File-system tells the kernel to invalidate cache for the given node id.
 917  */
 918 int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
 919                              loff_t offset, loff_t len);
 920
 921 /**
 922  * File-system tells the kernel to invalidate parent attributes and
 923  * the dentry matching parent/name.
 924  *
 925  * If the child_nodeid is non-zero and:
 926  *    - matches the inode number for the dentry matching parent/name,
 927  *    - is not a mount point
 928  *    - is a file or oan empty directory
 929  * then the dentry is unhashed (d_delete()).
 930  */
 931 int fuse_reverse_inval_entry(struct super_block *sb, u64 parent_nodeid,
 932                              u64 child_nodeid, struct qstr *name);
 933
 934 int fuse_do_open(struct fuse_conn *fc, u64 nodeid, struct file *file,
 935                  bool isdir);
 936
 937 /**
 938  * fuse_direct_io() flags
 939  */
 940
 941 /** If set, it is WRITE; otherwise - READ */
 942 #define FUSE_DIO_WRITE (1 << 0)
 943
 944 /** CUSE pass fuse_direct_io() a file which f_mapping->host is not from FUSE */
 945 #define FUSE_DIO_CUSE  (1 << 1)
 946
 947 ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter,
 948                        loff_t *ppos, int flags);
 949 long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
 950                    unsigned int flags);
 951 long fuse_ioctl_common(struct file *file, unsigned int cmd,
 952                        unsigned long arg, unsigned int flags);
 953 unsigned fuse_file_poll(struct file *file, poll_table *wait);
 954 int fuse_dev_release(struct inode *inode, struct file *file);
 955
 956 bool fuse_write_update_size(struct inode *inode, loff_t pos);
 957
 958 int fuse_flush_times(struct inode *inode, struct fuse_file *ff);
 959 int fuse_write_inode(struct inode *inode, struct writeback_control *wbc);
 960
 961 int fuse_do_setattr(struct inode *inode, struct iattr *attr,
 962                     struct file *file);
 963
 964 void fuse_set_initialized(struct fuse_conn *fc);
 965
 966 void fuse_unlock_inode(struct inode *inode);
 967 void fuse_lock_inode(struct inode *inode);
 968
 969 #endif /* _FS_FUSE_I_H */