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 #include <linux/xattr.h>
  27
  28 /** Max number of pages that can be used in a single read request */
  29 #define FUSE_MAX_PAGES_PER_REQ 32
  30
  31 /** Bias for fi->writectr, meaning new writepages must not be sent */
  32 #define FUSE_NOWRITE INT_MIN
  33
  34 /** It could be as large as PATH_MAX, but would that have any uses? */
  35 #define FUSE_NAME_MAX 1024
  36
  37 /** Number of dentries for each connection in the control filesystem */
  38 #define FUSE_CTL_NUM_DENTRIES 5
  39
  40 /** Number of page pointers embedded in fuse_req */
  41 #define FUSE_REQ_INLINE_PAGES 1
  42
  43 /** List of active connections */
  44 extern struct list_head fuse_conn_list;
  45
  46 /** Global mutex protecting fuse_conn_list and the control filesystem */
  47 extern struct mutex fuse_mutex;
  48
  49 /** Module parameters */
  50 extern unsigned max_user_bgreq;
  51 extern unsigned max_user_congthresh;
  52
  53 /* One forget request */
  54 struct fuse_forget_link {
  55         struct fuse_forget_one forget_one;
  56         struct fuse_forget_link *next;
  57 };
  58
  59 /** FUSE inode */
  60 struct fuse_inode {
  61         /** Inode data */
  62         struct inode inode;
  63
  64         /** Unique ID, which identifies the inode between userspace
  65          * and kernel */
  66         u64 nodeid;
  67
  68         /** Number of lookups on this inode */
  69         u64 nlookup;
  70
  71         /** The request used for sending the FORGET message */
  72         struct fuse_forget_link *forget;
  73
  74         /** Time in jiffies until the file attributes are valid */
  75         u64 i_time;
  76
  77         /** The sticky bit in inode->i_mode may have been removed, so
  78             preserve the original mode */
  79         umode_t orig_i_mode;
  80
  81         /** 64 bit inode number */
  82         u64 orig_ino;
  83
  84         /** Version of last attribute change */
  85         u64 attr_version;
  86
  87         /** Files usable in writepage.  Protected by fc->lock */
  88         struct list_head write_files;
  89
  90         /** Writepages pending on truncate or fsync */
  91         struct list_head queued_writes;
  92
  93         /** Number of sent writes, a negative bias (FUSE_NOWRITE)
  94          * means more writes are blocked */
  95         int writectr;
  96
  97         /** Waitq for writepage completion */
  98         wait_queue_head_t page_waitq;
  99
 100         /** List of writepage requestst (pending or sent) */
 101         struct list_head writepages;
 102
 103         /** Miscellaneous bits describing inode state */
 104         unsigned long state;
 105
 106         /** Lock for serializing lookup and readdir for back compatibility*/
 107         struct mutex mutex;
 108 };
 109
 110 /** FUSE inode state bits */
 111 enum {
 112         /** Advise readdirplus  */
 113         FUSE_I_ADVISE_RDPLUS,
 114         /** Initialized with readdirplus */
 115         FUSE_I_INIT_RDPLUS,
 116         /** An operation changing file size is in progress  */
 117         FUSE_I_SIZE_UNSTABLE,
 118 };
 119
 120 struct fuse_conn;
 121
 122 /** FUSE specific file data */
 123 struct fuse_file {
 124         /** Fuse connection for this file */
 125         struct fuse_conn *fc;
 126
 127         /** Request reserved for flush and release */
 128         struct fuse_req *reserved_req;
 129
 130         /** Kernel file handle guaranteed to be unique */
 131         u64 kh;
 132
 133         /** File handle used by userspace */
 134         u64 fh;
 135
 136         /** Node id of this file */
 137         u64 nodeid;
 138
 139         /** Refcount */
 140         atomic_t count;
 141
 142         /** FOPEN_* flags returned by open */
 143         u32 open_flags;
 144
 145         /** Entry on inode's write_files list */
 146         struct list_head write_entry;
 147
 148         /** RB node to be linked on fuse_conn->polled_files */
 149         struct rb_node polled_node;
 150
 151         /** Wait queue head for poll */
 152         wait_queue_head_t poll_wait;
 153
 154         /** Has flock been performed on this file? */
 155         bool flock:1;
 156 };
 157
 158 /** One input argument of a request */
 159 struct fuse_in_arg {
 160         unsigned size;
 161         const void *value;
 162 };
 163
 164 /** The request input */
 165 struct fuse_in {
 166         /** The request header */
 167         struct fuse_in_header h;
 168
 169         /** True if the data for the last argument is in req->pages */
 170         unsigned argpages:1;
 171
 172         /** Number of arguments */
 173         unsigned numargs;
 174
 175         /** Array of arguments */
 176         struct fuse_in_arg args[3];
 177 };
 178
 179 /** One output argument of a request */
 180 struct fuse_arg {
 181         unsigned size;
 182         void *value;
 183 };
 184
 185 /** The request output */
 186 struct fuse_out {
 187         /** Header returned from userspace */
 188         struct fuse_out_header h;
 189
 190         /*
 191          * The following bitfields are not changed during the request
 192          * processing
 193          */
 194
 195         /** Last argument is variable length (can be shorter than
 196             arg->size) */
 197         unsigned argvar:1;
 198
 199         /** Last argument is a list of pages to copy data to */
 200         unsigned argpages:1;
 201
 202         /** Zero partially or not copied pages */
 203         unsigned page_zeroing:1;
 204
 205         /** Pages may be replaced with new ones */
 206         unsigned page_replace:1;
 207
 208         /** Number or arguments */
 209         unsigned numargs;
 210
 211         /** Array of arguments */
 212         struct fuse_arg args[2];
 213 };
 214
 215 /** FUSE page descriptor */
 216 struct fuse_page_desc {
 217         unsigned int length;
 218         unsigned int offset;
 219 };
 220
 221 struct fuse_args {
 222         struct {
 223                 struct {
 224                         uint32_t opcode;
 225                         uint64_t nodeid;
 226                 } h;
 227                 unsigned numargs;
 228                 struct fuse_in_arg args[3];
 229
 230         } in;
 231         struct {
 232                 unsigned argvar:1;
 233                 unsigned numargs;
 234                 struct fuse_arg args[2];
 235         } out;
 236 };
 237
 238 #define FUSE_ARGS(args) struct fuse_args args = {}
 239
 240 /** The request IO state (for asynchronous processing) */
 241 struct fuse_io_priv {
 242         struct kref refcnt;
 243         int async;
 244         spinlock_t lock;
 245         unsigned reqs;
 246         ssize_t bytes;
 247         size_t size;
 248         __u64 offset;
 249         bool write;
 250         int err;
 251         struct kiocb *iocb;
 252         struct file *file;
 253         struct completion *done;
 254         bool blocking;
 255 };
 256
 257 #define FUSE_IO_PRIV_SYNC(f) \
 258 {                                       \
 259         .refcnt = { ATOMIC_INIT(1) },   \
 260         .async = 0,                     \
 261         .file = f,                      \
 262 }
 263
 264 /**
 265  * Request flags
 266  *
 267  * FR_ISREPLY:          set if the request has reply
 268  * FR_FORCE:            force sending of the request even if interrupted
 269  * FR_BACKGROUND:       request is sent in the background
 270  * FR_WAITING:          request is counted as "waiting"
 271  * FR_ABORTED:          the request was aborted
 272  * FR_INTERRUPTED:      the request has been interrupted
 273  * FR_LOCKED:           data is being copied to/from the request
 274  * FR_PENDING:          request is not yet in userspace
 275  * FR_SENT:             request is in userspace, waiting for an answer
 276  * FR_FINISHED:         request is finished
 277  * FR_PRIVATE:          request is on private list
 278  */
 279 enum fuse_req_flag {
 280         FR_ISREPLY,
 281         FR_FORCE,
 282         FR_BACKGROUND,
 283         FR_WAITING,
 284         FR_ABORTED,
 285         FR_INTERRUPTED,
 286         FR_LOCKED,
 287         FR_PENDING,
 288         FR_SENT,
 289         FR_FINISHED,
 290         FR_PRIVATE,
 291 };
 292
 293 /**
 294  * A request to the client
 295  *
 296  * .waitq.lock protects the following fields:
 297  *   - FR_ABORTED
 298  *   - FR_LOCKED (may also be modified under fc->lock, tested under both)
 299  */
 300 struct fuse_req {
 301         /** This can be on either pending processing or io lists in
 302             fuse_conn */
 303         struct list_head list;
 304
 305         /** Entry on the interrupts list  */
 306         struct list_head intr_entry;
 307
 308         /** refcount */
 309         atomic_t count;
 310
 311         /** Unique ID for the interrupt request */
 312         u64 intr_unique;
 313
 314         /* Request flags, updated with test/set/clear_bit() */
 315         unsigned long flags;
 316
 317         /** The request input */
 318         struct fuse_in in;
 319
 320         /** The request output */
 321         struct fuse_out out;
 322
 323         /** Used to wake up the task waiting for completion of request*/
 324         wait_queue_head_t waitq;
 325
 326         /** Data for asynchronous requests */
 327         union {
 328                 struct {
 329                         struct fuse_release_in in;
 330                         struct inode *inode;
 331                 } release;
 332                 struct fuse_init_in init_in;
 333                 struct fuse_init_out init_out;
 334                 struct cuse_init_in cuse_init_in;
 335                 struct {
 336                         struct fuse_read_in in;
 337                         u64 attr_ver;
 338                 } read;
 339                 struct {
 340                         struct fuse_write_in in;
 341                         struct fuse_write_out out;
 342                         struct fuse_req *next;
 343                 } write;
 344                 struct fuse_notify_retrieve_in retrieve_in;
 345         } misc;
 346
 347         /** page vector */
 348         struct page **pages;
 349
 350         /** page-descriptor vector */
 351         struct fuse_page_desc *page_descs;
 352
 353         /** size of the 'pages' array */
 354         unsigned max_pages;
 355
 356         /** inline page vector */
 357         struct page *inline_pages[FUSE_REQ_INLINE_PAGES];
 358
 359         /** inline page-descriptor vector */
 360         struct fuse_page_desc inline_page_descs[FUSE_REQ_INLINE_PAGES];
 361
 362         /** number of pages in vector */
 363         unsigned num_pages;
 364
 365         /** File used in the request (or NULL) */
 366         struct fuse_file *ff;
 367
 368         /** Inode used in the request or NULL */
 369         struct inode *inode;
 370
 371         /** AIO control block */
 372         struct fuse_io_priv *io;
 373
 374         /** Link on fi->writepages */
 375         struct list_head writepages_entry;
 376
 377         /** Request completion callback */
 378         void (*end)(struct fuse_conn *, struct fuse_req *);
 379
 380         /** Request is stolen from fuse_file->reserved_req */
 381         struct file *stolen_file;
 382 };
 383
 384 struct fuse_iqueue {
 385         /** Connection established */
 386         unsigned connected;
 387
 388         /** Readers of the connection are waiting on this */
 389         wait_queue_head_t waitq;
 390
 391         /** The next unique request id */
 392         u64 reqctr;
 393
 394         /** The list of pending requests */
 395         struct list_head pending;
 396
 397         /** Pending interrupts */
 398         struct list_head interrupts;
 399
 400         /** Queue of pending forgets */
 401         struct fuse_forget_link forget_list_head;
 402         struct fuse_forget_link *forget_list_tail;
 403
 404         /** Batching of FORGET requests (positive indicates FORGET batch) */
 405         int forget_batch;
 406
 407         /** O_ASYNC requests */
 408         struct fasync_struct *fasync;
 409 };
 410
 411 struct fuse_pqueue {
 412         /** Connection established */
 413         unsigned connected;
 414
 415         /** Lock protecting accessess to  members of this structure */
 416         spinlock_t lock;
 417
 418         /** The list of requests being processed */
 419         struct list_head processing;
 420
 421         /** The list of requests under I/O */
 422         struct list_head io;
 423 };
 424
 425 /**
 426  * Fuse device instance
 427  */
 428 struct fuse_dev {
 429         /** Fuse connection for this device */
 430         struct fuse_conn *fc;
 431
 432         /** Processing queue */
 433         struct fuse_pqueue pq;
 434
 435         /** list entry on fc->devices */
 436         struct list_head entry;
 437 };
 438
 439 /**
 440  * A Fuse connection.
 441  *
 442  * This structure is created, when the filesystem is mounted, and is
 443  * destroyed, when the client device is closed and the filesystem is
 444  * unmounted.
 445  */
 446 struct fuse_conn {
 447         /** Lock protecting accessess to  members of this structure */
 448         spinlock_t lock;
 449
 450         /** Refcount */
 451         atomic_t count;
 452
 453         /** Number of fuse_dev's */
 454         atomic_t dev_count;
 455
 456         struct rcu_head rcu;
 457
 458         /** The user id for this mount */
 459         kuid_t user_id;
 460
 461         /** The group id for this mount */
 462         kgid_t group_id;
 463
 464         /** Maximum read size */
 465         unsigned max_read;
 466
 467         /** Maximum write size */
 468         unsigned max_write;
 469
 470         /** Input queue */
 471         struct fuse_iqueue iq;
 472
 473         /** The next unique kernel file handle */
 474         u64 khctr;
 475
 476         /** rbtree of fuse_files waiting for poll events indexed by ph */
 477         struct rb_root polled_files;
 478
 479         /** Maximum number of outstanding background requests */
 480         unsigned max_background;
 481
 482         /** Number of background requests at which congestion starts */
 483         unsigned congestion_threshold;
 484
 485         /** Number of requests currently in the background */
 486         unsigned num_background;
 487
 488         /** Number of background requests currently queued for userspace */
 489         unsigned active_background;
 490
 491         /** The list of background requests set aside for later queuing */
 492         struct list_head bg_queue;
 493
 494         /** Flag indicating that INIT reply has been received. Allocating
 495          * any fuse request will be suspended until the flag is set */
 496         int initialized;
 497
 498         /** Flag indicating if connection is blocked.  This will be
 499             the case before the INIT reply is received, and if there
 500             are too many outstading backgrounds requests */
 501         int blocked;
 502
 503         /** waitq for blocked connection */
 504         wait_queue_head_t blocked_waitq;
 505
 506         /** waitq for reserved requests */
 507         wait_queue_head_t reserved_req_waitq;
 508
 509         /** Connection established, cleared on umount, connection
 510             abort and device release */
 511         unsigned connected;
 512
 513         /** Connection failed (version mismatch).  Cannot race with
 514             setting other bitfields since it is only set once in INIT
 515             reply, before any other request, and never cleared */
 516         unsigned conn_error:1;
 517
 518         /** Connection successful.  Only set in INIT */
 519         unsigned conn_init:1;
 520
 521         /** Do readpages asynchronously?  Only set in INIT */
 522         unsigned async_read:1;
 523
 524         /** Do not send separate SETATTR request before open(O_TRUNC)  */
 525         unsigned atomic_o_trunc:1;
 526
 527         /** Filesystem supports NFS exporting.  Only set in INIT */
 528         unsigned export_support:1;
 529
 530         /** Set if bdi is valid */
 531         unsigned bdi_initialized:1;
 532
 533         /** write-back cache policy (default is write-through) */
 534         unsigned writeback_cache:1;
 535
 536         /** allow parallel lookups and readdir (default is serialized) */
 537         unsigned parallel_dirops:1;
 538
 539         /** handle fs handles killing suid/sgid/cap on write/chown/trunc */
 540         unsigned handle_killpriv:1;
 541
 542         /*
 543          * The following bitfields are only for optimization purposes
 544          * and hence races in setting them will not cause malfunction
 545          */
 546
 547         /** Is open/release not implemented by fs? */
 548         unsigned no_open:1;
 549
 550         /** Is fsync not implemented by fs? */
 551         unsigned no_fsync:1;
 552
 553         /** Is fsyncdir not implemented by fs? */
 554         unsigned no_fsyncdir:1;
 555
 556         /** Is flush not implemented by fs? */
 557         unsigned no_flush:1;
 558
 559         /** Is setxattr not implemented by fs? */
 560         unsigned no_setxattr:1;
 561
 562         /** Is getxattr not implemented by fs? */
 563         unsigned no_getxattr:1;
 564
 565         /** Is listxattr not implemented by fs? */
 566         unsigned no_listxattr:1;
 567
 568         /** Is removexattr not implemented by fs? */
 569         unsigned no_removexattr:1;
 570
 571         /** Are posix file locking primitives not implemented by fs? */
 572         unsigned no_lock:1;
 573
 574         /** Is access not implemented by fs? */
 575         unsigned no_access:1;
 576
 577         /** Is create not implemented by fs? */
 578         unsigned no_create:1;
 579
 580         /** Is interrupt not implemented by fs? */
 581         unsigned no_interrupt:1;
 582
 583         /** Is bmap not implemented by fs? */
 584         unsigned no_bmap:1;
 585
 586         /** Is poll not implemented by fs? */
 587         unsigned no_poll:1;
 588
 589         /** Do multi-page cached writes */
 590         unsigned big_writes:1;
 591
 592         /** Don't apply umask to creation modes */
 593         unsigned dont_mask:1;
 594
 595         /** Are BSD file locking primitives not implemented by fs? */
 596         unsigned no_flock:1;
 597
 598         /** Is fallocate not implemented by fs? */
 599         unsigned no_fallocate:1;
 600
 601         /** Is rename with flags implemented by fs? */
 602         unsigned no_rename2:1;
 603
 604         /** Use enhanced/automatic page cache invalidation. */
 605         unsigned auto_inval_data:1;
 606
 607         /** Does the filesystem support readdirplus? */
 608         unsigned do_readdirplus:1;
 609
 610         /** Does the filesystem want adaptive readdirplus? */
 611         unsigned readdirplus_auto:1;
 612
 613         /** Does the filesystem support asynchronous direct-IO submission? */
 614         unsigned async_dio:1;
 615
 616         /** Is lseek not implemented by fs? */
 617         unsigned no_lseek:1;
 618
 619         /** Does the filesystem support posix acls? */
 620         unsigned posix_acl:1;
 621
 622         /** Check permissions based on the file mode or not? */
 623         unsigned default_permissions:1;
 624
 625         /** Allow other than the mounter user to access the filesystem ? */
 626         unsigned allow_other:1;
 627
 628         /** The number of requests waiting for completion */
 629         atomic_t num_waiting;
 630
 631         /** Negotiated minor version */
 632         unsigned minor;
 633
 634         /** Backing dev info */
 635         struct backing_dev_info bdi;
 636
 637         /** Entry on the fuse_conn_list */
 638         struct list_head entry;
 639
 640         /** Device ID from super block */
 641         dev_t dev;
 642
 643         /** Dentries in the control filesystem */
 644         struct dentry *ctl_dentry[FUSE_CTL_NUM_DENTRIES];
 645
 646         /** number of dentries used in the above array */
 647         int ctl_ndents;
 648
 649         /** Key for lock owner ID scrambling */
 650         u32 scramble_key[4];
 651
 652         /** Reserved request for the DESTROY message */
 653         struct fuse_req *destroy_req;
 654
 655         /** Version counter for attribute changes */
 656         u64 attr_version;
 657
 658         /** Called on final put */
 659         void (*release)(struct fuse_conn *);
 660
 661         /** Super block for this connection. */
 662         struct super_block *sb;
 663
 664         /** Read/write semaphore to hold when accessing sb. */
 665         struct rw_semaphore killsb;
 666
 667         /** List of device instances belonging to this connection */
 668         struct list_head devices;
 669 };
 670
 671 static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
 672 {
 673         return sb->s_fs_info;
 674 }
 675
 676 static inline struct fuse_conn *get_fuse_conn(struct inode *inode)
 677 {
 678         return get_fuse_conn_super(inode->i_sb);
 679 }
 680
 681 static inline struct fuse_inode *get_fuse_inode(struct inode *inode)
 682 {
 683         return container_of(inode, struct fuse_inode, inode);
 684 }
 685
 686 static inline u64 get_node_id(struct inode *inode)
 687 {
 688         return get_fuse_inode(inode)->nodeid;
 689 }
 690
 691 /** Device operations */
 692 extern const struct file_operations fuse_dev_operations;
 693
 694 extern const struct dentry_operations fuse_dentry_operations;
 695 extern const struct dentry_operations fuse_root_dentry_operations;
 696
 697 /**
 698  * Inode to nodeid comparison.
 699  */
 700 int fuse_inode_eq(struct inode *inode, void *_nodeidp);
 701
 702 /**
 703  * Get a filled in inode
 704  */
 705 struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
 706                         int generation, struct fuse_attr *attr,
 707                         u64 attr_valid, u64 attr_version);
 708
 709 int fuse_lookup_name(struct super_block *sb, u64 nodeid, const struct qstr *name,
 710                      struct fuse_entry_out *outarg, struct inode **inode);
 711
 712 /**
 713  * Send FORGET command
 714  */
 715 void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget,
 716                        u64 nodeid, u64 nlookup);
 717
 718 struct fuse_forget_link *fuse_alloc_forget(void);
 719
 720 /* Used by READDIRPLUS */
 721 void fuse_force_forget(struct file *file, u64 nodeid);
 722
 723 /**
 724  * Initialize READ or READDIR request
 725  */
 726 void fuse_read_fill(struct fuse_req *req, struct file *file,
 727                     loff_t pos, size_t count, int opcode);
 728
 729 /**
 730  * Send OPEN or OPENDIR request
 731  */
 732 int fuse_open_common(struct inode *inode, struct file *file, bool isdir);
 733
 734 struct fuse_file *fuse_file_alloc(struct fuse_conn *fc);
 735 struct fuse_file *fuse_file_get(struct fuse_file *ff);
 736 void fuse_file_free(struct fuse_file *ff);
 737 void fuse_finish_open(struct inode *inode, struct file *file);
 738
 739 void fuse_sync_release(struct fuse_file *ff, int flags);
 740
 741 /**
 742  * Send RELEASE or RELEASEDIR request
 743  */
 744 void fuse_release_common(struct file *file, int opcode);
 745
 746 /**
 747  * Send FSYNC or FSYNCDIR request
 748  */
 749 int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
 750                       int datasync, int isdir);
 751
 752 /**
 753  * Notify poll wakeup
 754  */
 755 int fuse_notify_poll_wakeup(struct fuse_conn *fc,
 756                             struct fuse_notify_poll_wakeup_out *outarg);
 757
 758 /**
 759  * Initialize file operations on a regular file
 760  */
 761 void fuse_init_file_inode(struct inode *inode);
 762
 763 /**
 764  * Initialize inode operations on regular files and special files
 765  */
 766 void fuse_init_common(struct inode *inode);
 767
 768 /**
 769  * Initialize inode and file operations on a directory
 770  */
 771 void fuse_init_dir(struct inode *inode);
 772
 773 /**
 774  * Initialize inode operations on a symlink
 775  */
 776 void fuse_init_symlink(struct inode *inode);
 777
 778 /**
 779  * Change attributes of an inode
 780  */
 781 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
 782                             u64 attr_valid, u64 attr_version);
 783
 784 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
 785                                    u64 attr_valid);
 786
 787 /**
 788  * Initialize the client device
 789  */
 790 int fuse_dev_init(void);
 791
 792 /**
 793  * Cleanup the client device
 794  */
 795 void fuse_dev_cleanup(void);
 796
 797 int fuse_ctl_init(void);
 798 void __exit fuse_ctl_cleanup(void);
 799
 800 /**
 801  * Allocate a request
 802  */
 803 struct fuse_req *fuse_request_alloc(unsigned npages);
 804
 805 struct fuse_req *fuse_request_alloc_nofs(unsigned npages);
 806
 807 /**
 808  * Free a request
 809  */
 810 void fuse_request_free(struct fuse_req *req);
 811
 812 /**
 813  * Get a request, may fail with -ENOMEM,
 814  * caller should specify # elements in req->pages[] explicitly
 815  */
 816 struct fuse_req *fuse_get_req(struct fuse_conn *fc, unsigned npages);
 817 struct fuse_req *fuse_get_req_for_background(struct fuse_conn *fc,
 818                                              unsigned npages);
 819
 820 /*
 821  * Increment reference count on request
 822  */
 823 void __fuse_get_request(struct fuse_req *req);
 824
 825 /**
 826  * Gets a requests for a file operation, always succeeds
 827  */
 828 struct fuse_req *fuse_get_req_nofail_nopages(struct fuse_conn *fc,
 829                                              struct file *file);
 830
 831 /**
 832  * Decrement reference count of a request.  If count goes to zero free
 833  * the request.
 834  */
 835 void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req);
 836
 837 /**
 838  * Send a request (synchronous)
 839  */
 840 void fuse_request_send(struct fuse_conn *fc, struct fuse_req *req);
 841
 842 /**
 843  * Simple request sending that does request allocation and freeing
 844  */
 845 ssize_t fuse_simple_request(struct fuse_conn *fc, struct fuse_args *args);
 846
 847 /**
 848  * Send a request in the background
 849  */
 850 void fuse_request_send_background(struct fuse_conn *fc, struct fuse_req *req);
 851
 852 void fuse_request_send_background_locked(struct fuse_conn *fc,
 853                                          struct fuse_req *req);
 854
 855 /* Abort all requests */
 856 void fuse_abort_conn(struct fuse_conn *fc);
 857
 858 /**
 859  * Invalidate inode attributes
 860  */
 861 void fuse_invalidate_attr(struct inode *inode);
 862
 863 void fuse_invalidate_entry_cache(struct dentry *entry);
 864
 865 void fuse_invalidate_atime(struct inode *inode);
 866
 867 /**
 868  * Acquire reference to fuse_conn
 869  */
 870 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc);
 871
 872 /**
 873  * Initialize fuse_conn
 874  */
 875 void fuse_conn_init(struct fuse_conn *fc);
 876
 877 /**
 878  * Release reference to fuse_conn
 879  */
 880 void fuse_conn_put(struct fuse_conn *fc);
 881
 882 struct fuse_dev *fuse_dev_alloc(struct fuse_conn *fc);
 883 void fuse_dev_free(struct fuse_dev *fud);
 884
 885 /**
 886  * Add connection to control filesystem
 887  */
 888 int fuse_ctl_add_conn(struct fuse_conn *fc);
 889
 890 /**
 891  * Remove connection from control filesystem
 892  */
 893 void fuse_ctl_remove_conn(struct fuse_conn *fc);
 894
 895 /**
 896  * Is file type valid?
 897  */
 898 int fuse_valid_type(int m);
 899
 900 /**
 901  * Is current process allowed to perform filesystem operation?
 902  */
 903 int fuse_allow_current_process(struct fuse_conn *fc);
 904
 905 u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id);
 906
 907 void fuse_update_ctime(struct inode *inode);
 908
 909 int fuse_update_attributes(struct inode *inode, struct kstat *stat,
 910                            struct file *file, bool *refreshed);
 911
 912 void fuse_flush_writepages(struct inode *inode);
 913
 914 void fuse_set_nowrite(struct inode *inode);
 915 void fuse_release_nowrite(struct inode *inode);
 916
 917 u64 fuse_get_attr_version(struct fuse_conn *fc);
 918
 919 /**
 920  * File-system tells the kernel to invalidate cache for the given node id.
 921  */
 922 int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
 923                              loff_t offset, loff_t len);
 924
 925 /**
 926  * File-system tells the kernel to invalidate parent attributes and
 927  * the dentry matching parent/name.
 928  *
 929  * If the child_nodeid is non-zero and:
 930  *    - matches the inode number for the dentry matching parent/name,
 931  *    - is not a mount point
 932  *    - is a file or oan empty directory
 933  * then the dentry is unhashed (d_delete()).
 934  */
 935 int fuse_reverse_inval_entry(struct super_block *sb, u64 parent_nodeid,
 936                              u64 child_nodeid, struct qstr *name);
 937
 938 int fuse_do_open(struct fuse_conn *fc, u64 nodeid, struct file *file,
 939                  bool isdir);
 940
 941 /**
 942  * fuse_direct_io() flags
 943  */
 944
 945 /** If set, it is WRITE; otherwise - READ */
 946 #define FUSE_DIO_WRITE (1 << 0)
 947
 948 /** CUSE pass fuse_direct_io() a file which f_mapping->host is not from FUSE */
 949 #define FUSE_DIO_CUSE  (1 << 1)
 950
 951 ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter,
 952                        loff_t *ppos, int flags);
 953 long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
 954                    unsigned int flags);
 955 long fuse_ioctl_common(struct file *file, unsigned int cmd,
 956                        unsigned long arg, unsigned int flags);
 957 unsigned fuse_file_poll(struct file *file, poll_table *wait);
 958 int fuse_dev_release(struct inode *inode, struct file *file);
 959
 960 bool fuse_write_update_size(struct inode *inode, loff_t pos);
 961
 962 int fuse_flush_times(struct inode *inode, struct fuse_file *ff);
 963 int fuse_write_inode(struct inode *inode, struct writeback_control *wbc);
 964
 965 int fuse_do_setattr(struct dentry *dentry, struct iattr *attr,
 966                     struct file *file);
 967
 968 void fuse_set_initialized(struct fuse_conn *fc);
 969
 970 void fuse_unlock_inode(struct inode *inode);
 971 void fuse_lock_inode(struct inode *inode);
 972
 973 int fuse_setxattr(struct inode *inode, const char *name, const void *value,
 974                   size_t size, int flags);
 975 ssize_t fuse_getxattr(struct inode *inode, const char *name, void *value,
 976                       size_t size);
 977 ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size);
 978 int fuse_removexattr(struct inode *inode, const char *name);
 979 extern const struct xattr_handler *fuse_xattr_handlers[];
 980 extern const struct xattr_handler *fuse_acl_xattr_handlers[];
 981
 982 struct posix_acl;
 983 struct posix_acl *fuse_get_acl(struct inode *inode, int type);
 984 int fuse_set_acl(struct inode *inode, struct posix_acl *acl, int type);
 985
 986 #endif /* _FS_FUSE_I_H */