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 #include <linux/pid_namespace.h>
  28 #include <linux/user_namespace.h>
  29
  30 /** Max number of pages that can be used in a single read request */
  31 #define FUSE_MAX_PAGES_PER_REQ 32
  32
  33 /** Bias for fi->writectr, meaning new writepages must not be sent */
  34 #define FUSE_NOWRITE INT_MIN
  35
  36 /** It could be as large as PATH_MAX, but would that have any uses? */
  37 #define FUSE_NAME_MAX 1024
  38
  39 /** Number of dentries for each connection in the control filesystem */
  40 #define FUSE_CTL_NUM_DENTRIES 5
  41
  42 /** Number of page pointers embedded in fuse_req */
  43 #define FUSE_REQ_INLINE_PAGES 1
  44
  45 /** List of active connections */
  46 extern struct list_head fuse_conn_list;
  47
  48 /** Global mutex protecting fuse_conn_list and the control filesystem */
  49 extern struct mutex fuse_mutex;
  50
  51 /** Module parameters */
  52 extern unsigned max_user_bgreq;
  53 extern unsigned max_user_congthresh;
  54
  55 /* One forget request */
  56 struct fuse_forget_link {
  57         struct fuse_forget_one forget_one;
  58         struct fuse_forget_link *next;
  59 };
  60
  61 /** FUSE inode */
  62 struct fuse_inode {
  63         /** Inode data */
  64         struct inode inode;
  65
  66         /** Unique ID, which identifies the inode between userspace
  67          * and kernel */
  68         u64 nodeid;
  69
  70         /** Number of lookups on this inode */
  71         u64 nlookup;
  72
  73         /** The request used for sending the FORGET message */
  74         struct fuse_forget_link *forget;
  75
  76         /** Time in jiffies until the file attributes are valid */
  77         u64 i_time;
  78
  79         /** The sticky bit in inode->i_mode may have been removed, so
  80             preserve the original mode */
  81         umode_t orig_i_mode;
  82
  83         /** 64 bit inode number */
  84         u64 orig_ino;
  85
  86         /** Version of last attribute change */
  87         u64 attr_version;
  88
  89         /** Files usable in writepage.  Protected by fc->lock */
  90         struct list_head write_files;
  91
  92         /** Writepages pending on truncate or fsync */
  93         struct list_head queued_writes;
  94
  95         /** Number of sent writes, a negative bias (FUSE_NOWRITE)
  96          * means more writes are blocked */
  97         int writectr;
  98
  99         /** Waitq for writepage completion */
 100         wait_queue_head_t page_waitq;
 101
 102         /** List of writepage requestst (pending or sent) */
 103         struct list_head writepages;
 104
 105         /** Miscellaneous bits describing inode state */
 106         unsigned long state;
 107
 108         /** Lock for serializing lookup and readdir for back compatibility*/
 109         struct mutex mutex;
 110 };
 111
 112 /** FUSE inode state bits */
 113 enum {
 114         /** Advise readdirplus  */
 115         FUSE_I_ADVISE_RDPLUS,
 116         /** Initialized with readdirplus */
 117         FUSE_I_INIT_RDPLUS,
 118         /** An operation changing file size is in progress  */
 119         FUSE_I_SIZE_UNSTABLE,
 120 };
 121
 122 struct fuse_conn;
 123
 124 /** FUSE specific file data */
 125 struct fuse_file {
 126         /** Fuse connection for this file */
 127         struct fuse_conn *fc;
 128
 129         /** Request reserved for flush and release */
 130         struct fuse_req *reserved_req;
 131
 132         /** Kernel file handle guaranteed to be unique */
 133         u64 kh;
 134
 135         /** File handle used by userspace */
 136         u64 fh;
 137
 138         /** Node id of this file */
 139         u64 nodeid;
 140
 141         /** Refcount */
 142         atomic_t count;
 143
 144         /** FOPEN_* flags returned by open */
 145         u32 open_flags;
 146
 147         /** Entry on inode's write_files list */
 148         struct list_head write_entry;
 149
 150         /** RB node to be linked on fuse_conn->polled_files */
 151         struct rb_node polled_node;
 152
 153         /** Wait queue head for poll */
 154         wait_queue_head_t poll_wait;
 155
 156         /** Has flock been performed on this file? */
 157         bool flock:1;
 158 };
 159
 160 /** One input argument of a request */
 161 struct fuse_in_arg {
 162         unsigned size;
 163         const void *value;
 164 };
 165
 166 /** The request input */
 167 struct fuse_in {
 168         /** The request header */
 169         struct fuse_in_header h;
 170
 171         /** True if the data for the last argument is in req->pages */
 172         unsigned argpages:1;
 173
 174         /** Number of arguments */
 175         unsigned numargs;
 176
 177         /** Array of arguments */
 178         struct fuse_in_arg args[3];
 179 };
 180
 181 /** One output argument of a request */
 182 struct fuse_arg {
 183         unsigned size;
 184         void *value;
 185 };
 186
 187 /** The request output */
 188 struct fuse_out {
 189         /** Header returned from userspace */
 190         struct fuse_out_header h;
 191
 192         /*
 193          * The following bitfields are not changed during the request
 194          * processing
 195          */
 196
 197         /** Last argument is variable length (can be shorter than
 198             arg->size) */
 199         unsigned argvar:1;
 200
 201         /** Last argument is a list of pages to copy data to */
 202         unsigned argpages:1;
 203
 204         /** Zero partially or not copied pages */
 205         unsigned page_zeroing:1;
 206
 207         /** Pages may be replaced with new ones */
 208         unsigned page_replace:1;
 209
 210         /** Number or arguments */
 211         unsigned numargs;
 212
 213         /** Array of arguments */
 214         struct fuse_arg args[2];
 215 };
 216
 217 /** FUSE page descriptor */
 218 struct fuse_page_desc {
 219         unsigned int length;
 220         unsigned int offset;
 221 };
 222
 223 struct fuse_args {
 224         struct {
 225                 struct {
 226                         uint32_t opcode;
 227                         uint64_t nodeid;
 228                 } h;
 229                 unsigned numargs;
 230                 struct fuse_in_arg args[3];
 231
 232         } in;
 233         struct {
 234                 unsigned argvar:1;
 235                 unsigned numargs;
 236                 struct fuse_arg args[2];
 237         } out;
 238 };
 239
 240 #define FUSE_ARGS(args) struct fuse_args args = {}
 241
 242 /** The request IO state (for asynchronous processing) */
 243 struct fuse_io_priv {
 244         struct kref refcnt;
 245         int async;
 246         spinlock_t lock;
 247         unsigned reqs;
 248         ssize_t bytes;
 249         size_t size;
 250         __u64 offset;
 251         bool write;
 252         int err;
 253         struct kiocb *iocb;
 254         struct file *file;
 255         struct completion *done;
 256         bool blocking;
 257 };
 258
 259 #define FUSE_IO_PRIV_SYNC(f) \
 260 {                                       \
 261         .refcnt = { ATOMIC_INIT(1) },   \
 262         .async = 0,                     \
 263         .file = f,                      \
 264 }
 265
 266 /**
 267  * Request flags
 268  *
 269  * FR_ISREPLY:          set if the request has reply
 270  * FR_FORCE:            force sending of the request even if interrupted
 271  * FR_BACKGROUND:       request is sent in the background
 272  * FR_WAITING:          request is counted as "waiting"
 273  * FR_ABORTED:          the request was aborted
 274  * FR_INTERRUPTED:      the request has been interrupted
 275  * FR_LOCKED:           data is being copied to/from the request
 276  * FR_PENDING:          request is not yet in userspace
 277  * FR_SENT:             request is in userspace, waiting for an answer
 278  * FR_FINISHED:         request is finished
 279  * FR_PRIVATE:          request is on private list
 280  */
 281 enum fuse_req_flag {
 282         FR_ISREPLY,
 283         FR_FORCE,
 284         FR_BACKGROUND,
 285         FR_WAITING,
 286         FR_ABORTED,
 287         FR_INTERRUPTED,
 288         FR_LOCKED,
 289         FR_PENDING,
 290         FR_SENT,
 291         FR_FINISHED,
 292         FR_PRIVATE,
 293 };
 294
 295 /**
 296  * A request to the client
 297  *
 298  * .waitq.lock protects the following fields:
 299  *   - FR_ABORTED
 300  *   - FR_LOCKED (may also be modified under fc->lock, tested under both)
 301  */
 302 struct fuse_req {
 303         /** This can be on either pending processing or io lists in
 304             fuse_conn */
 305         struct list_head list;
 306
 307         /** Entry on the interrupts list  */
 308         struct list_head intr_entry;
 309
 310         /** refcount */
 311         atomic_t count;
 312
 313         /** Unique ID for the interrupt request */
 314         u64 intr_unique;
 315
 316         /* Request flags, updated with test/set/clear_bit() */
 317         unsigned long flags;
 318
 319         /** The request input */
 320         struct fuse_in in;
 321
 322         /** The request output */
 323         struct fuse_out out;
 324
 325         /** Used to wake up the task waiting for completion of request*/
 326         wait_queue_head_t waitq;
 327
 328         /** Data for asynchronous requests */
 329         union {
 330                 struct {
 331                         struct fuse_release_in in;
 332                         struct inode *inode;
 333                 } release;
 334                 struct fuse_init_in init_in;
 335                 struct fuse_init_out init_out;
 336                 struct cuse_init_in cuse_init_in;
 337                 struct {
 338                         struct fuse_read_in in;
 339                         u64 attr_ver;
 340                 } read;
 341                 struct {
 342                         struct fuse_write_in in;
 343                         struct fuse_write_out out;
 344                         struct fuse_req *next;
 345                 } write;
 346                 struct fuse_notify_retrieve_in retrieve_in;
 347         } misc;
 348
 349         /** page vector */
 350         struct page **pages;
 351
 352         /** page-descriptor vector */
 353         struct fuse_page_desc *page_descs;
 354
 355         /** size of the 'pages' array */
 356         unsigned max_pages;
 357
 358         /** inline page vector */
 359         struct page *inline_pages[FUSE_REQ_INLINE_PAGES];
 360
 361         /** inline page-descriptor vector */
 362         struct fuse_page_desc inline_page_descs[FUSE_REQ_INLINE_PAGES];
 363
 364         /** number of pages in vector */
 365         unsigned num_pages;
 366
 367         /** File used in the request (or NULL) */
 368         struct fuse_file *ff;
 369
 370         /** Inode used in the request or NULL */
 371         struct inode *inode;
 372
 373         /** AIO control block */
 374         struct fuse_io_priv *io;
 375
 376         /** Link on fi->writepages */
 377         struct list_head writepages_entry;
 378
 379         /** Request completion callback */
 380         void (*end)(struct fuse_conn *, struct fuse_req *);
 381
 382         /** Request is stolen from fuse_file->reserved_req */
 383         struct file *stolen_file;
 384 };
 385
 386 struct fuse_iqueue {
 387         /** Connection established */
 388         unsigned connected;
 389
 390         /** Readers of the connection are waiting on this */
 391         wait_queue_head_t waitq;
 392
 393         /** The next unique request id */
 394         u64 reqctr;
 395
 396         /** The list of pending requests */
 397         struct list_head pending;
 398
 399         /** Pending interrupts */
 400         struct list_head interrupts;
 401
 402         /** Queue of pending forgets */
 403         struct fuse_forget_link forget_list_head;
 404         struct fuse_forget_link *forget_list_tail;
 405
 406         /** Batching of FORGET requests (positive indicates FORGET batch) */
 407         int forget_batch;
 408
 409         /** O_ASYNC requests */
 410         struct fasync_struct *fasync;
 411 };
 412
 413 struct fuse_pqueue {
 414         /** Connection established */
 415         unsigned connected;
 416
 417         /** Lock protecting accessess to  members of this structure */
 418         spinlock_t lock;
 419
 420         /** The list of requests being processed */
 421         struct list_head processing;
 422
 423         /** The list of requests under I/O */
 424         struct list_head io;
 425 };
 426
 427 /**
 428  * Fuse device instance
 429  */
 430 struct fuse_dev {
 431         /** Fuse connection for this device */
 432         struct fuse_conn *fc;
 433
 434         /** Processing queue */
 435         struct fuse_pqueue pq;
 436
 437         /** list entry on fc->devices */
 438         struct list_head entry;
 439 };
 440
 441 /**
 442  * A Fuse connection.
 443  *
 444  * This structure is created, when the filesystem is mounted, and is
 445  * destroyed, when the client device is closed and the filesystem is
 446  * unmounted.
 447  */
 448 struct fuse_conn {
 449         /** Lock protecting accessess to  members of this structure */
 450         spinlock_t lock;
 451
 452         /** Refcount */
 453         atomic_t count;
 454
 455         /** Number of fuse_dev's */
 456         atomic_t dev_count;
 457
 458         struct rcu_head rcu;
 459
 460         /** The user id for this mount */
 461         kuid_t user_id;
 462
 463         /** The group id for this mount */
 464         kgid_t group_id;
 465
 466         /** The pid namespace for this mount */
 467         struct pid_namespace *pid_ns;
 468
 469         /** The user namespace for this mount */
 470         struct user_namespace *user_ns;
 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         /** allow parallel lookups and readdir (default is serialized) */
 545         unsigned parallel_dirops:1;
 546
 547         /** handle fs handles killing suid/sgid/cap on write/chown/trunc */
 548         unsigned handle_killpriv: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         /** Does the filesystem support posix acls? */
 628         unsigned posix_acl:1;
 629
 630         /** Check permissions based on the file mode or not? */
 631         unsigned default_permissions:1;
 632
 633         /** Allow other than the mounter user to access the filesystem ? */
 634         unsigned allow_other:1;
 635
 636         /** The number of requests waiting for completion */
 637         atomic_t num_waiting;
 638
 639         /** Negotiated minor version */
 640         unsigned minor;
 641
 642         /** Backing dev info */
 643         struct backing_dev_info bdi;
 644
 645         /** Entry on the fuse_conn_list */
 646         struct list_head entry;
 647
 648         /** Device ID from super block */
 649         dev_t dev;
 650
 651         /** Dentries in the control filesystem */
 652         struct dentry *ctl_dentry[FUSE_CTL_NUM_DENTRIES];
 653
 654         /** number of dentries used in the above array */
 655         int ctl_ndents;
 656
 657         /** Key for lock owner ID scrambling */
 658         u32 scramble_key[4];
 659
 660         /** Reserved request for the DESTROY message */
 661         struct fuse_req *destroy_req;
 662
 663         /** Version counter for attribute changes */
 664         u64 attr_version;
 665
 666         /** Called on final put */
 667         void (*release)(struct fuse_conn *);
 668
 669         /** Super block for this connection. */
 670         struct super_block *sb;
 671
 672         /** Read/write semaphore to hold when accessing sb. */
 673         struct rw_semaphore killsb;
 674
 675         /** List of device instances belonging to this connection */
 676         struct list_head devices;
 677 };
 678
 679 static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
 680 {
 681         return sb->s_fs_info;
 682 }
 683
 684 static inline struct fuse_conn *get_fuse_conn(struct inode *inode)
 685 {
 686         return get_fuse_conn_super(inode->i_sb);
 687 }
 688
 689 static inline struct fuse_inode *get_fuse_inode(struct inode *inode)
 690 {
 691         return container_of(inode, struct fuse_inode, inode);
 692 }
 693
 694 static inline u64 get_node_id(struct inode *inode)
 695 {
 696         return get_fuse_inode(inode)->nodeid;
 697 }
 698
 699 /** Device operations */
 700 extern const struct file_operations fuse_dev_operations;
 701
 702 extern const struct dentry_operations fuse_dentry_operations;
 703 extern const struct dentry_operations fuse_root_dentry_operations;
 704
 705 /**
 706  * Inode to nodeid comparison.
 707  */
 708 int fuse_inode_eq(struct inode *inode, void *_nodeidp);
 709
 710 /**
 711  * Get a filled in inode
 712  */
 713 struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
 714                         int generation, struct fuse_attr *attr,
 715                         u64 attr_valid, u64 attr_version);
 716
 717 int fuse_lookup_name(struct super_block *sb, u64 nodeid, const struct qstr *name,
 718                      struct fuse_entry_out *outarg, struct inode **inode);
 719
 720 /**
 721  * Send FORGET command
 722  */
 723 void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget,
 724                        u64 nodeid, u64 nlookup);
 725
 726 struct fuse_forget_link *fuse_alloc_forget(void);
 727
 728 /* Used by READDIRPLUS */
 729 void fuse_force_forget(struct file *file, u64 nodeid);
 730
 731 /**
 732  * Initialize READ or READDIR request
 733  */
 734 void fuse_read_fill(struct fuse_req *req, struct file *file,
 735                     loff_t pos, size_t count, int opcode);
 736
 737 /**
 738  * Send OPEN or OPENDIR request
 739  */
 740 int fuse_open_common(struct inode *inode, struct file *file, bool isdir);
 741
 742 struct fuse_file *fuse_file_alloc(struct fuse_conn *fc);
 743 struct fuse_file *fuse_file_get(struct fuse_file *ff);
 744 void fuse_file_free(struct fuse_file *ff);
 745 void fuse_finish_open(struct inode *inode, struct file *file);
 746
 747 void fuse_sync_release(struct fuse_file *ff, int flags);
 748
 749 /**
 750  * Send RELEASE or RELEASEDIR request
 751  */
 752 void fuse_release_common(struct file *file, int opcode);
 753
 754 /**
 755  * Send FSYNC or FSYNCDIR request
 756  */
 757 int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
 758                       int datasync, int isdir);
 759
 760 /**
 761  * Notify poll wakeup
 762  */
 763 int fuse_notify_poll_wakeup(struct fuse_conn *fc,
 764                             struct fuse_notify_poll_wakeup_out *outarg);
 765
 766 /**
 767  * Initialize file operations on a regular file
 768  */
 769 void fuse_init_file_inode(struct inode *inode);
 770
 771 /**
 772  * Initialize inode operations on regular files and special files
 773  */
 774 void fuse_init_common(struct inode *inode);
 775
 776 /**
 777  * Initialize inode and file operations on a directory
 778  */
 779 void fuse_init_dir(struct inode *inode);
 780
 781 /**
 782  * Initialize inode operations on a symlink
 783  */
 784 void fuse_init_symlink(struct inode *inode);
 785
 786 /**
 787  * Change attributes of an inode
 788  */
 789 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
 790                             u64 attr_valid, u64 attr_version);
 791
 792 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
 793                                    u64 attr_valid);
 794
 795 /**
 796  * Initialize the client device
 797  */
 798 int fuse_dev_init(void);
 799
 800 /**
 801  * Cleanup the client device
 802  */
 803 void fuse_dev_cleanup(void);
 804
 805 int fuse_ctl_init(void);
 806 void __exit fuse_ctl_cleanup(void);
 807
 808 /**
 809  * Allocate a request
 810  */
 811 struct fuse_req *fuse_request_alloc(unsigned npages);
 812
 813 struct fuse_req *fuse_request_alloc_nofs(unsigned npages);
 814
 815 /**
 816  * Free a request
 817  */
 818 void fuse_request_free(struct fuse_req *req);
 819
 820 /**
 821  * Get a request, may fail with -ENOMEM,
 822  * caller should specify # elements in req->pages[] explicitly
 823  */
 824 struct fuse_req *fuse_get_req(struct fuse_conn *fc, unsigned npages);
 825 struct fuse_req *fuse_get_req_for_background(struct fuse_conn *fc,
 826                                              unsigned npages);
 827
 828 /*
 829  * Increment reference count on request
 830  */
 831 void __fuse_get_request(struct fuse_req *req);
 832
 833 /**
 834  * Gets a requests for a file operation, always succeeds
 835  */
 836 struct fuse_req *fuse_get_req_nofail_nopages(struct fuse_conn *fc,
 837                                              struct file *file);
 838
 839 /**
 840  * Decrement reference count of a request.  If count goes to zero free
 841  * the request.
 842  */
 843 void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req);
 844
 845 /**
 846  * Send a request (synchronous)
 847  */
 848 void fuse_request_send(struct fuse_conn *fc, struct fuse_req *req);
 849
 850 /**
 851  * Simple request sending that does request allocation and freeing
 852  */
 853 ssize_t fuse_simple_request(struct fuse_conn *fc, struct fuse_args *args);
 854
 855 /**
 856  * Send a request in the background
 857  */
 858 void fuse_request_send_background(struct fuse_conn *fc, struct fuse_req *req);
 859
 860 void fuse_request_send_background_locked(struct fuse_conn *fc,
 861                                          struct fuse_req *req);
 862
 863 /* Abort all requests */
 864 void fuse_abort_conn(struct fuse_conn *fc);
 865
 866 /**
 867  * Invalidate inode attributes
 868  */
 869 void fuse_invalidate_attr(struct inode *inode);
 870
 871 void fuse_invalidate_entry_cache(struct dentry *entry);
 872
 873 void fuse_invalidate_atime(struct inode *inode);
 874
 875 /**
 876  * Acquire reference to fuse_conn
 877  */
 878 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc);
 879
 880 /**
 881  * Initialize fuse_conn
 882  */
 883 void fuse_conn_init(struct fuse_conn *fc, struct user_namespace *user_ns);
 884
 885 /**
 886  * Release reference to fuse_conn
 887  */
 888 void fuse_conn_put(struct fuse_conn *fc);
 889
 890 struct fuse_dev *fuse_dev_alloc(struct fuse_conn *fc);
 891 void fuse_dev_free(struct fuse_dev *fud);
 892
 893 /**
 894  * Add connection to control filesystem
 895  */
 896 int fuse_ctl_add_conn(struct fuse_conn *fc);
 897
 898 /**
 899  * Remove connection from control filesystem
 900  */
 901 void fuse_ctl_remove_conn(struct fuse_conn *fc);
 902
 903 /**
 904  * Is file type valid?
 905  */
 906 int fuse_valid_type(int m);
 907
 908 /**
 909  * Is current process allowed to perform filesystem operation?
 910  */
 911 int fuse_allow_current_process(struct fuse_conn *fc);
 912
 913 u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id);
 914
 915 void fuse_update_ctime(struct inode *inode);
 916
 917 int fuse_update_attributes(struct inode *inode, struct kstat *stat,
 918                            struct file *file, bool *refreshed);
 919
 920 void fuse_flush_writepages(struct inode *inode);
 921
 922 void fuse_set_nowrite(struct inode *inode);
 923 void fuse_release_nowrite(struct inode *inode);
 924
 925 u64 fuse_get_attr_version(struct fuse_conn *fc);
 926
 927 /**
 928  * File-system tells the kernel to invalidate cache for the given node id.
 929  */
 930 int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
 931                              loff_t offset, loff_t len);
 932
 933 /**
 934  * File-system tells the kernel to invalidate parent attributes and
 935  * the dentry matching parent/name.
 936  *
 937  * If the child_nodeid is non-zero and:
 938  *    - matches the inode number for the dentry matching parent/name,
 939  *    - is not a mount point
 940  *    - is a file or oan empty directory
 941  * then the dentry is unhashed (d_delete()).
 942  */
 943 int fuse_reverse_inval_entry(struct super_block *sb, u64 parent_nodeid,
 944                              u64 child_nodeid, struct qstr *name);
 945
 946 int fuse_do_open(struct fuse_conn *fc, u64 nodeid, struct file *file,
 947                  bool isdir);
 948
 949 /**
 950  * fuse_direct_io() flags
 951  */
 952
 953 /** If set, it is WRITE; otherwise - READ */
 954 #define FUSE_DIO_WRITE (1 << 0)
 955
 956 /** CUSE pass fuse_direct_io() a file which f_mapping->host is not from FUSE */
 957 #define FUSE_DIO_CUSE  (1 << 1)
 958
 959 ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter,
 960                        loff_t *ppos, int flags);
 961 long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
 962                    unsigned int flags);
 963 long fuse_ioctl_common(struct file *file, unsigned int cmd,
 964                        unsigned long arg, unsigned int flags);
 965 unsigned fuse_file_poll(struct file *file, poll_table *wait);
 966 int fuse_dev_release(struct inode *inode, struct file *file);
 967
 968 bool fuse_write_update_size(struct inode *inode, loff_t pos);
 969
 970 int fuse_flush_times(struct inode *inode, struct fuse_file *ff);
 971 int fuse_write_inode(struct inode *inode, struct writeback_control *wbc);
 972
 973 int fuse_do_setattr(struct dentry *dentry, struct iattr *attr,
 974                     struct file *file);
 975
 976 void fuse_set_initialized(struct fuse_conn *fc);
 977
 978 void fuse_unlock_inode(struct inode *inode);
 979 void fuse_lock_inode(struct inode *inode);
 980
 981 int fuse_setxattr(struct inode *inode, const char *name, const void *value,
 982                   size_t size, int flags);
 983 ssize_t fuse_getxattr(struct inode *inode, const char *name, void *value,
 984                       size_t size);
 985 ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size);
 986 int fuse_removexattr(struct inode *inode, const char *name);
 987 extern const struct xattr_handler *fuse_xattr_handlers[];
 988 extern const struct xattr_handler *fuse_acl_xattr_handlers[];
 989
 990 struct posix_acl;
 991 struct posix_acl *fuse_get_acl(struct inode *inode, int type);
 992 int fuse_set_acl(struct inode *inode, struct posix_acl *acl, int type);
 993
 994 #endif /* _FS_FUSE_I_H */