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 /** If the FUSE_DEFAULT_PERMISSIONS flag is given, the filesystem
  41     module will check permissions based on the file mode.  Otherwise no
  42     permission checking is done in the kernel */
  43 #define FUSE_DEFAULT_PERMISSIONS (1 << 0)
  44
  45 /** If the FUSE_ALLOW_OTHER flag is given, then not only the user
  46     doing the mount will be allowed to access the filesystem */
  47 #define FUSE_ALLOW_OTHER         (1 << 1)
  48
  49 /** Number of page pointers embedded in fuse_req */
  50 #define FUSE_REQ_INLINE_PAGES 1
  51
  52 /** List of active connections */
  53 extern struct list_head fuse_conn_list;
  54
  55 /** Global mutex protecting fuse_conn_list and the control filesystem */
  56 extern struct mutex fuse_mutex;
  57
  58 /** Module parameters */
  59 extern unsigned max_user_bgreq;
  60 extern unsigned max_user_congthresh;
  61
  62 /* One forget request */
  63 struct fuse_forget_link {
  64         struct fuse_forget_one forget_one;
  65         struct fuse_forget_link *next;
  66 };
  67
  68 /** FUSE inode */
  69 struct fuse_inode {
  70         /** Inode data */
  71         struct inode inode;
  72
  73         /** Unique ID, which identifies the inode between userspace
  74          * and kernel */
  75         u64 nodeid;
  76
  77         /** Number of lookups on this inode */
  78         u64 nlookup;
  79
  80         /** The request used for sending the FORGET message */
  81         struct fuse_forget_link *forget;
  82
  83         /** Time in jiffies until the file attributes are valid */
  84         u64 i_time;
  85
  86         /** The sticky bit in inode->i_mode may have been removed, so
  87             preserve the original mode */
  88         umode_t orig_i_mode;
  89
  90         /** 64 bit inode number */
  91         u64 orig_ino;
  92
  93         /** Version of last attribute change */
  94         u64 attr_version;
  95
  96         /** Files usable in writepage.  Protected by fc->lock */
  97         struct list_head write_files;
  98
  99         /** Writepages pending on truncate or fsync */
 100         struct list_head queued_writes;
 101
 102         /** Number of sent writes, a negative bias (FUSE_NOWRITE)
 103          * means more writes are blocked */
 104         int writectr;
 105
 106         /** Waitq for writepage completion */
 107         wait_queue_head_t page_waitq;
 108
 109         /** List of writepage requestst (pending or sent) */
 110         struct list_head writepages;
 111
 112         /** Miscellaneous bits describing inode state */
 113         unsigned long state;
 114
 115         /** Lock for serializing lookup and readdir for back compatibility*/
 116         struct mutex mutex;
 117 };
 118
 119 /** FUSE inode state bits */
 120 enum {
 121         /** Advise readdirplus  */
 122         FUSE_I_ADVISE_RDPLUS,
 123         /** Initialized with readdirplus */
 124         FUSE_I_INIT_RDPLUS,
 125         /** An operation changing file size is in progress  */
 126         FUSE_I_SIZE_UNSTABLE,
 127 };
 128
 129 struct fuse_conn;
 130
 131 /** FUSE specific file data */
 132 struct fuse_file {
 133         /** Fuse connection for this file */
 134         struct fuse_conn *fc;
 135
 136         /** Request reserved for flush and release */
 137         struct fuse_req *reserved_req;
 138
 139         /** Kernel file handle guaranteed to be unique */
 140         u64 kh;
 141
 142         /** File handle used by userspace */
 143         u64 fh;
 144
 145         /** Node id of this file */
 146         u64 nodeid;
 147
 148         /** Refcount */
 149         atomic_t count;
 150
 151         /** FOPEN_* flags returned by open */
 152         u32 open_flags;
 153
 154         /** Entry on inode's write_files list */
 155         struct list_head write_entry;
 156
 157         /** RB node to be linked on fuse_conn->polled_files */
 158         struct rb_node polled_node;
 159
 160         /** Wait queue head for poll */
 161         wait_queue_head_t poll_wait;
 162
 163         /** Has flock been performed on this file? */
 164         bool flock:1;
 165 };
 166
 167 /** One input argument of a request */
 168 struct fuse_in_arg {
 169         unsigned size;
 170         const void *value;
 171 };
 172
 173 /** The request input */
 174 struct fuse_in {
 175         /** The request header */
 176         struct fuse_in_header h;
 177
 178         /** True if the data for the last argument is in req->pages */
 179         unsigned argpages:1;
 180
 181         /** Number of arguments */
 182         unsigned numargs;
 183
 184         /** Array of arguments */
 185         struct fuse_in_arg args[3];
 186 };
 187
 188 /** One output argument of a request */
 189 struct fuse_arg {
 190         unsigned size;
 191         void *value;
 192 };
 193
 194 /** The request output */
 195 struct fuse_out {
 196         /** Header returned from userspace */
 197         struct fuse_out_header h;
 198
 199         /*
 200          * The following bitfields are not changed during the request
 201          * processing
 202          */
 203
 204         /** Last argument is variable length (can be shorter than
 205             arg->size) */
 206         unsigned argvar:1;
 207
 208         /** Last argument is a list of pages to copy data to */
 209         unsigned argpages:1;
 210
 211         /** Zero partially or not copied pages */
 212         unsigned page_zeroing:1;
 213
 214         /** Pages may be replaced with new ones */
 215         unsigned page_replace:1;
 216
 217         /** Number or arguments */
 218         unsigned numargs;
 219
 220         /** Array of arguments */
 221         struct fuse_arg args[2];
 222 };
 223
 224 /** FUSE page descriptor */
 225 struct fuse_page_desc {
 226         unsigned int length;
 227         unsigned int offset;
 228 };
 229
 230 struct fuse_args {
 231         struct {
 232                 struct {
 233                         uint32_t opcode;
 234                         uint64_t nodeid;
 235                 } h;
 236                 unsigned numargs;
 237                 struct fuse_in_arg args[3];
 238
 239         } in;
 240         struct {
 241                 unsigned argvar:1;
 242                 unsigned numargs;
 243                 struct fuse_arg args[2];
 244         } out;
 245 };
 246
 247 #define FUSE_ARGS(args) struct fuse_args args = {}
 248
 249 /** The request IO state (for asynchronous processing) */
 250 struct fuse_io_priv {
 251         struct kref refcnt;
 252         int async;
 253         spinlock_t lock;
 254         unsigned reqs;
 255         ssize_t bytes;
 256         size_t size;
 257         __u64 offset;
 258         bool write;
 259         int err;
 260         struct kiocb *iocb;
 261         struct file *file;
 262         struct completion *done;
 263         bool blocking;
 264 };
 265
 266 #define FUSE_IO_PRIV_SYNC(f) \
 267 {                                       \
 268         .refcnt = { ATOMIC_INIT(1) },   \
 269         .async = 0,                     \
 270         .file = f,                      \
 271 }
 272
 273 /**
 274  * Request flags
 275  *
 276  * FR_ISREPLY:          set if the request has reply
 277  * FR_FORCE:            force sending of the request even if interrupted
 278  * FR_BACKGROUND:       request is sent in the background
 279  * FR_WAITING:          request is counted as "waiting"
 280  * FR_ABORTED:          the request was aborted
 281  * FR_INTERRUPTED:      the request has been interrupted
 282  * FR_LOCKED:           data is being copied to/from the request
 283  * FR_PENDING:          request is not yet in userspace
 284  * FR_SENT:             request is in userspace, waiting for an answer
 285  * FR_FINISHED:         request is finished
 286  * FR_PRIVATE:          request is on private list
 287  */
 288 enum fuse_req_flag {
 289         FR_ISREPLY,
 290         FR_FORCE,
 291         FR_BACKGROUND,
 292         FR_WAITING,
 293         FR_ABORTED,
 294         FR_INTERRUPTED,
 295         FR_LOCKED,
 296         FR_PENDING,
 297         FR_SENT,
 298         FR_FINISHED,
 299         FR_PRIVATE,
 300 };
 301
 302 /**
 303  * A request to the client
 304  *
 305  * .waitq.lock protects the following fields:
 306  *   - FR_ABORTED
 307  *   - FR_LOCKED (may also be modified under fc->lock, tested under both)
 308  */
 309 struct fuse_req {
 310         /** This can be on either pending processing or io lists in
 311             fuse_conn */
 312         struct list_head list;
 313
 314         /** Entry on the interrupts list  */
 315         struct list_head intr_entry;
 316
 317         /** refcount */
 318         atomic_t count;
 319
 320         /** Unique ID for the interrupt request */
 321         u64 intr_unique;
 322
 323         /* Request flags, updated with test/set/clear_bit() */
 324         unsigned long flags;
 325
 326         /** The request input */
 327         struct fuse_in in;
 328
 329         /** The request output */
 330         struct fuse_out out;
 331
 332         /** Used to wake up the task waiting for completion of request*/
 333         wait_queue_head_t waitq;
 334
 335         /** Data for asynchronous requests */
 336         union {
 337                 struct {
 338                         struct fuse_release_in in;
 339                         struct inode *inode;
 340                 } release;
 341                 struct fuse_init_in init_in;
 342                 struct fuse_init_out init_out;
 343                 struct cuse_init_in cuse_init_in;
 344                 struct {
 345                         struct fuse_read_in in;
 346                         u64 attr_ver;
 347                 } read;
 348                 struct {
 349                         struct fuse_write_in in;
 350                         struct fuse_write_out out;
 351                         struct fuse_req *next;
 352                 } write;
 353                 struct fuse_notify_retrieve_in retrieve_in;
 354         } misc;
 355
 356         /** page vector */
 357         struct page **pages;
 358
 359         /** page-descriptor vector */
 360         struct fuse_page_desc *page_descs;
 361
 362         /** size of the 'pages' array */
 363         unsigned max_pages;
 364
 365         /** inline page vector */
 366         struct page *inline_pages[FUSE_REQ_INLINE_PAGES];
 367
 368         /** inline page-descriptor vector */
 369         struct fuse_page_desc inline_page_descs[FUSE_REQ_INLINE_PAGES];
 370
 371         /** number of pages in vector */
 372         unsigned num_pages;
 373
 374         /** File used in the request (or NULL) */
 375         struct fuse_file *ff;
 376
 377         /** Inode used in the request or NULL */
 378         struct inode *inode;
 379
 380         /** AIO control block */
 381         struct fuse_io_priv *io;
 382
 383         /** Link on fi->writepages */
 384         struct list_head writepages_entry;
 385
 386         /** Request completion callback */
 387         void (*end)(struct fuse_conn *, struct fuse_req *);
 388
 389         /** Request is stolen from fuse_file->reserved_req */
 390         struct file *stolen_file;
 391 };
 392
 393 struct fuse_iqueue {
 394         /** Connection established */
 395         unsigned connected;
 396
 397         /** Readers of the connection are waiting on this */
 398         wait_queue_head_t waitq;
 399
 400         /** The next unique request id */
 401         u64 reqctr;
 402
 403         /** The list of pending requests */
 404         struct list_head pending;
 405
 406         /** Pending interrupts */
 407         struct list_head interrupts;
 408
 409         /** Queue of pending forgets */
 410         struct fuse_forget_link forget_list_head;
 411         struct fuse_forget_link *forget_list_tail;
 412
 413         /** Batching of FORGET requests (positive indicates FORGET batch) */
 414         int forget_batch;
 415
 416         /** O_ASYNC requests */
 417         struct fasync_struct *fasync;
 418 };
 419
 420 struct fuse_pqueue {
 421         /** Connection established */
 422         unsigned connected;
 423
 424         /** Lock protecting accessess to  members of this structure */
 425         spinlock_t lock;
 426
 427         /** The list of requests being processed */
 428         struct list_head processing;
 429
 430         /** The list of requests under I/O */
 431         struct list_head io;
 432 };
 433
 434 /**
 435  * Fuse device instance
 436  */
 437 struct fuse_dev {
 438         /** Fuse connection for this device */
 439         struct fuse_conn *fc;
 440
 441         /** Processing queue */
 442         struct fuse_pqueue pq;
 443
 444         /** list entry on fc->devices */
 445         struct list_head entry;
 446 };
 447
 448 /**
 449  * A Fuse connection.
 450  *
 451  * This structure is created, when the filesystem is mounted, and is
 452  * destroyed, when the client device is closed and the filesystem is
 453  * unmounted.
 454  */
 455 struct fuse_conn {
 456         /** Lock protecting accessess to  members of this structure */
 457         spinlock_t lock;
 458
 459         /** Refcount */
 460         atomic_t count;
 461
 462         /** Number of fuse_dev's */
 463         atomic_t dev_count;
 464
 465         struct rcu_head rcu;
 466
 467         /** The user id for this mount */
 468         kuid_t user_id;
 469
 470         /** The group id for this mount */
 471         kgid_t group_id;
 472
 473         /** The fuse mount flags for this mount */
 474         unsigned flags;
 475
 476         /** Maximum read size */
 477         unsigned max_read;
 478
 479         /** Maximum write size */
 480         unsigned max_write;
 481
 482         /** Input queue */
 483         struct fuse_iqueue iq;
 484
 485         /** The next unique kernel file handle */
 486         u64 khctr;
 487
 488         /** rbtree of fuse_files waiting for poll events indexed by ph */
 489         struct rb_root polled_files;
 490
 491         /** Maximum number of outstanding background requests */
 492         unsigned max_background;
 493
 494         /** Number of background requests at which congestion starts */
 495         unsigned congestion_threshold;
 496
 497         /** Number of requests currently in the background */
 498         unsigned num_background;
 499
 500         /** Number of background requests currently queued for userspace */
 501         unsigned active_background;
 502
 503         /** The list of background requests set aside for later queuing */
 504         struct list_head bg_queue;
 505
 506         /** Flag indicating that INIT reply has been received. Allocating
 507          * any fuse request will be suspended until the flag is set */
 508         int initialized;
 509
 510         /** Flag indicating if connection is blocked.  This will be
 511             the case before the INIT reply is received, and if there
 512             are too many outstading backgrounds requests */
 513         int blocked;
 514
 515         /** waitq for blocked connection */
 516         wait_queue_head_t blocked_waitq;
 517
 518         /** waitq for reserved requests */
 519         wait_queue_head_t reserved_req_waitq;
 520
 521         /** Connection established, cleared on umount, connection
 522             abort and device release */
 523         unsigned connected;
 524
 525         /** Connection failed (version mismatch).  Cannot race with
 526             setting other bitfields since it is only set once in INIT
 527             reply, before any other request, and never cleared */
 528         unsigned conn_error:1;
 529
 530         /** Connection successful.  Only set in INIT */
 531         unsigned conn_init:1;
 532
 533         /** Do readpages asynchronously?  Only set in INIT */
 534         unsigned async_read:1;
 535
 536         /** Do not send separate SETATTR request before open(O_TRUNC)  */
 537         unsigned atomic_o_trunc:1;
 538
 539         /** Filesystem supports NFS exporting.  Only set in INIT */
 540         unsigned export_support:1;
 541
 542         /** Set if bdi is valid */
 543         unsigned bdi_initialized:1;
 544
 545         /** write-back cache policy (default is write-through) */
 546         unsigned writeback_cache:1;
 547
 548         /** allow parallel lookups and readdir (default is serialized) */
 549         unsigned parallel_dirops:1;
 550
 551         /** handle fs handles killing suid/sgid/cap on write/chown/trunc */
 552         unsigned handle_killpriv:1;
 553
 554         /*
 555          * The following bitfields are only for optimization purposes
 556          * and hence races in setting them will not cause malfunction
 557          */
 558
 559         /** Is open/release not implemented by fs? */
 560         unsigned no_open:1;
 561
 562         /** Is fsync not implemented by fs? */
 563         unsigned no_fsync:1;
 564
 565         /** Is fsyncdir not implemented by fs? */
 566         unsigned no_fsyncdir:1;
 567
 568         /** Is flush not implemented by fs? */
 569         unsigned no_flush:1;
 570
 571         /** Is setxattr not implemented by fs? */
 572         unsigned no_setxattr:1;
 573
 574         /** Is getxattr not implemented by fs? */
 575         unsigned no_getxattr:1;
 576
 577         /** Is listxattr not implemented by fs? */
 578         unsigned no_listxattr:1;
 579
 580         /** Is removexattr not implemented by fs? */
 581         unsigned no_removexattr:1;
 582
 583         /** Are posix file locking primitives not implemented by fs? */
 584         unsigned no_lock:1;
 585
 586         /** Is access not implemented by fs? */
 587         unsigned no_access:1;
 588
 589         /** Is create not implemented by fs? */
 590         unsigned no_create:1;
 591
 592         /** Is interrupt not implemented by fs? */
 593         unsigned no_interrupt:1;
 594
 595         /** Is bmap not implemented by fs? */
 596         unsigned no_bmap:1;
 597
 598         /** Is poll not implemented by fs? */
 599         unsigned no_poll:1;
 600
 601         /** Do multi-page cached writes */
 602         unsigned big_writes:1;
 603
 604         /** Don't apply umask to creation modes */
 605         unsigned dont_mask:1;
 606
 607         /** Are BSD file locking primitives not implemented by fs? */
 608         unsigned no_flock:1;
 609
 610         /** Is fallocate not implemented by fs? */
 611         unsigned no_fallocate:1;
 612
 613         /** Is rename with flags implemented by fs? */
 614         unsigned no_rename2:1;
 615
 616         /** Use enhanced/automatic page cache invalidation. */
 617         unsigned auto_inval_data:1;
 618
 619         /** Does the filesystem support readdirplus? */
 620         unsigned do_readdirplus:1;
 621
 622         /** Does the filesystem want adaptive readdirplus? */
 623         unsigned readdirplus_auto:1;
 624
 625         /** Does the filesystem support asynchronous direct-IO submission? */
 626         unsigned async_dio:1;
 627
 628         /** Is lseek not implemented by fs? */
 629         unsigned no_lseek:1;
 630
 631         /** Does the filesystem support posix acls? */
 632         unsigned posix_acl:1;
 633
 634         /** The number of requests waiting for completion */
 635         atomic_t num_waiting;
 636
 637         /** Negotiated minor version */
 638         unsigned minor;
 639
 640         /** Backing dev info */
 641         struct backing_dev_info bdi;
 642
 643         /** Entry on the fuse_conn_list */
 644         struct list_head entry;
 645
 646         /** Device ID from super block */
 647         dev_t dev;
 648
 649         /** Dentries in the control filesystem */
 650         struct dentry *ctl_dentry[FUSE_CTL_NUM_DENTRIES];
 651
 652         /** number of dentries used in the above array */
 653         int ctl_ndents;
 654
 655         /** Key for lock owner ID scrambling */
 656         u32 scramble_key[4];
 657
 658         /** Reserved request for the DESTROY message */
 659         struct fuse_req *destroy_req;
 660
 661         /** Version counter for attribute changes */
 662         u64 attr_version;
 663
 664         /** Called on final put */
 665         void (*release)(struct fuse_conn *);
 666
 667         /** Super block for this connection. */
 668         struct super_block *sb;
 669
 670         /** Read/write semaphore to hold when accessing sb. */
 671         struct rw_semaphore killsb;
 672
 673         /** List of device instances belonging to this connection */
 674         struct list_head devices;
 675 };
 676
 677 static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
 678 {
 679         return sb->s_fs_info;
 680 }
 681
 682 static inline struct fuse_conn *get_fuse_conn(struct inode *inode)
 683 {
 684         return get_fuse_conn_super(inode->i_sb);
 685 }
 686
 687 static inline struct fuse_inode *get_fuse_inode(struct inode *inode)
 688 {
 689         return container_of(inode, struct fuse_inode, inode);
 690 }
 691
 692 static inline u64 get_node_id(struct inode *inode)
 693 {
 694         return get_fuse_inode(inode)->nodeid;
 695 }
 696
 697 /** Device operations */
 698 extern const struct file_operations fuse_dev_operations;
 699
 700 extern const struct dentry_operations fuse_dentry_operations;
 701
 702 /**
 703  * Inode to nodeid comparison.
 704  */
 705 int fuse_inode_eq(struct inode *inode, void *_nodeidp);
 706
 707 /**
 708  * Get a filled in inode
 709  */
 710 struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
 711                         int generation, struct fuse_attr *attr,
 712                         u64 attr_valid, u64 attr_version);
 713
 714 int fuse_lookup_name(struct super_block *sb, u64 nodeid, const struct qstr *name,
 715                      struct fuse_entry_out *outarg, struct inode **inode);
 716
 717 /**
 718  * Send FORGET command
 719  */
 720 void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget,
 721                        u64 nodeid, u64 nlookup);
 722
 723 struct fuse_forget_link *fuse_alloc_forget(void);
 724
 725 /* Used by READDIRPLUS */
 726 void fuse_force_forget(struct file *file, u64 nodeid);
 727
 728 /**
 729  * Initialize READ or READDIR request
 730  */
 731 void fuse_read_fill(struct fuse_req *req, struct file *file,
 732                     loff_t pos, size_t count, int opcode);
 733
 734 /**
 735  * Send OPEN or OPENDIR request
 736  */
 737 int fuse_open_common(struct inode *inode, struct file *file, bool isdir);
 738
 739 struct fuse_file *fuse_file_alloc(struct fuse_conn *fc);
 740 struct fuse_file *fuse_file_get(struct fuse_file *ff);
 741 void fuse_file_free(struct fuse_file *ff);
 742 void fuse_finish_open(struct inode *inode, struct file *file);
 743
 744 void fuse_sync_release(struct fuse_file *ff, int flags);
 745
 746 /**
 747  * Send RELEASE or RELEASEDIR request
 748  */
 749 void fuse_release_common(struct file *file, int opcode);
 750
 751 /**
 752  * Send FSYNC or FSYNCDIR request
 753  */
 754 int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
 755                       int datasync, int isdir);
 756
 757 /**
 758  * Notify poll wakeup
 759  */
 760 int fuse_notify_poll_wakeup(struct fuse_conn *fc,
 761                             struct fuse_notify_poll_wakeup_out *outarg);
 762
 763 /**
 764  * Initialize file operations on a regular file
 765  */
 766 void fuse_init_file_inode(struct inode *inode);
 767
 768 /**
 769  * Initialize inode operations on regular files and special files
 770  */
 771 void fuse_init_common(struct inode *inode);
 772
 773 /**
 774  * Initialize inode and file operations on a directory
 775  */
 776 void fuse_init_dir(struct inode *inode);
 777
 778 /**
 779  * Initialize inode operations on a symlink
 780  */
 781 void fuse_init_symlink(struct inode *inode);
 782
 783 /**
 784  * Change attributes of an inode
 785  */
 786 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
 787                             u64 attr_valid, u64 attr_version);
 788
 789 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
 790                                    u64 attr_valid);
 791
 792 /**
 793  * Initialize the client device
 794  */
 795 int fuse_dev_init(void);
 796
 797 /**
 798  * Cleanup the client device
 799  */
 800 void fuse_dev_cleanup(void);
 801
 802 int fuse_ctl_init(void);
 803 void __exit fuse_ctl_cleanup(void);
 804
 805 /**
 806  * Allocate a request
 807  */
 808 struct fuse_req *fuse_request_alloc(unsigned npages);
 809
 810 struct fuse_req *fuse_request_alloc_nofs(unsigned npages);
 811
 812 /**
 813  * Free a request
 814  */
 815 void fuse_request_free(struct fuse_req *req);
 816
 817 /**
 818  * Get a request, may fail with -ENOMEM,
 819  * caller should specify # elements in req->pages[] explicitly
 820  */
 821 struct fuse_req *fuse_get_req(struct fuse_conn *fc, unsigned npages);
 822 struct fuse_req *fuse_get_req_for_background(struct fuse_conn *fc,
 823                                              unsigned npages);
 824
 825 /*
 826  * Increment reference count on request
 827  */
 828 void __fuse_get_request(struct fuse_req *req);
 829
 830 /**
 831  * Gets a requests for a file operation, always succeeds
 832  */
 833 struct fuse_req *fuse_get_req_nofail_nopages(struct fuse_conn *fc,
 834                                              struct file *file);
 835
 836 /**
 837  * Decrement reference count of a request.  If count goes to zero free
 838  * the request.
 839  */
 840 void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req);
 841
 842 /**
 843  * Send a request (synchronous)
 844  */
 845 void fuse_request_send(struct fuse_conn *fc, struct fuse_req *req);
 846
 847 /**
 848  * Simple request sending that does request allocation and freeing
 849  */
 850 ssize_t fuse_simple_request(struct fuse_conn *fc, struct fuse_args *args);
 851
 852 /**
 853  * Send a request in the background
 854  */
 855 void fuse_request_send_background(struct fuse_conn *fc, struct fuse_req *req);
 856
 857 void fuse_request_send_background_locked(struct fuse_conn *fc,
 858                                          struct fuse_req *req);
 859
 860 /* Abort all requests */
 861 void fuse_abort_conn(struct fuse_conn *fc);
 862
 863 /**
 864  * Invalidate inode attributes
 865  */
 866 void fuse_invalidate_attr(struct inode *inode);
 867
 868 void fuse_invalidate_entry_cache(struct dentry *entry);
 869
 870 void fuse_invalidate_atime(struct inode *inode);
 871
 872 /**
 873  * Acquire reference to fuse_conn
 874  */
 875 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc);
 876
 877 /**
 878  * Initialize fuse_conn
 879  */
 880 void fuse_conn_init(struct fuse_conn *fc);
 881
 882 /**
 883  * Release reference to fuse_conn
 884  */
 885 void fuse_conn_put(struct fuse_conn *fc);
 886
 887 struct fuse_dev *fuse_dev_alloc(struct fuse_conn *fc);
 888 void fuse_dev_free(struct fuse_dev *fud);
 889
 890 /**
 891  * Add connection to control filesystem
 892  */
 893 int fuse_ctl_add_conn(struct fuse_conn *fc);
 894
 895 /**
 896  * Remove connection from control filesystem
 897  */
 898 void fuse_ctl_remove_conn(struct fuse_conn *fc);
 899
 900 /**
 901  * Is file type valid?
 902  */
 903 int fuse_valid_type(int m);
 904
 905 /**
 906  * Is current process allowed to perform filesystem operation?
 907  */
 908 int fuse_allow_current_process(struct fuse_conn *fc);
 909
 910 u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id);
 911
 912 void fuse_update_ctime(struct inode *inode);
 913
 914 int fuse_update_attributes(struct inode *inode, struct kstat *stat,
 915                            struct file *file, bool *refreshed);
 916
 917 void fuse_flush_writepages(struct inode *inode);
 918
 919 void fuse_set_nowrite(struct inode *inode);
 920 void fuse_release_nowrite(struct inode *inode);
 921
 922 u64 fuse_get_attr_version(struct fuse_conn *fc);
 923
 924 /**
 925  * File-system tells the kernel to invalidate cache for the given node id.
 926  */
 927 int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
 928                              loff_t offset, loff_t len);
 929
 930 /**
 931  * File-system tells the kernel to invalidate parent attributes and
 932  * the dentry matching parent/name.
 933  *
 934  * If the child_nodeid is non-zero and:
 935  *    - matches the inode number for the dentry matching parent/name,
 936  *    - is not a mount point
 937  *    - is a file or oan empty directory
 938  * then the dentry is unhashed (d_delete()).
 939  */
 940 int fuse_reverse_inval_entry(struct super_block *sb, u64 parent_nodeid,
 941                              u64 child_nodeid, struct qstr *name);
 942
 943 int fuse_do_open(struct fuse_conn *fc, u64 nodeid, struct file *file,
 944                  bool isdir);
 945
 946 /**
 947  * fuse_direct_io() flags
 948  */
 949
 950 /** If set, it is WRITE; otherwise - READ */
 951 #define FUSE_DIO_WRITE (1 << 0)
 952
 953 /** CUSE pass fuse_direct_io() a file which f_mapping->host is not from FUSE */
 954 #define FUSE_DIO_CUSE  (1 << 1)
 955
 956 ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter,
 957                        loff_t *ppos, int flags);
 958 long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
 959                    unsigned int flags);
 960 long fuse_ioctl_common(struct file *file, unsigned int cmd,
 961                        unsigned long arg, unsigned int flags);
 962 unsigned fuse_file_poll(struct file *file, poll_table *wait);
 963 int fuse_dev_release(struct inode *inode, struct file *file);
 964
 965 bool fuse_write_update_size(struct inode *inode, loff_t pos);
 966
 967 int fuse_flush_times(struct inode *inode, struct fuse_file *ff);
 968 int fuse_write_inode(struct inode *inode, struct writeback_control *wbc);
 969
 970 int fuse_do_setattr(struct inode *inode, struct iattr *attr,
 971                     struct file *file);
 972
 973 void fuse_set_initialized(struct fuse_conn *fc);
 974
 975 void fuse_unlock_inode(struct inode *inode);
 976 void fuse_lock_inode(struct inode *inode);
 977
 978 int fuse_setxattr(struct inode *inode, const char *name, const void *value,
 979                   size_t size, int flags);
 980 ssize_t fuse_getxattr(struct inode *inode, const char *name, void *value,
 981                       size_t size);
 982 ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size);
 983 int fuse_removexattr(struct inode *inode, const char *name);
 984 extern const struct xattr_handler *fuse_xattr_handlers[];
 985 extern const struct xattr_handler *fuse_acl_xattr_handlers[];
 986
 987 struct posix_acl;
 988 struct posix_acl *fuse_get_acl(struct inode *inode, int type);
 989 int fuse_set_acl(struct inode *inode, struct posix_acl *acl, int type);
 990
 991 #endif /* _FS_FUSE_I_H */