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/refcount.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         refcount_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         bool should_dirty;
 253         int err;
 254         struct kiocb *iocb;
 255         struct file *file;
 256         struct completion *done;
 257         bool blocking;
 258 };
 259
 260 #define FUSE_IO_PRIV_SYNC(f) \
 261 {                                       \
 262         .refcnt = KREF_INIT(1),         \
 263         .async = 0,                     \
 264         .file = f,                      \
 265 }
 266
 267 /**
 268  * Request flags
 269  *
 270  * FR_ISREPLY:          set if the request has reply
 271  * FR_FORCE:            force sending of the request even if interrupted
 272  * FR_BACKGROUND:       request is sent in the background
 273  * FR_WAITING:          request is counted as "waiting"
 274  * FR_ABORTED:          the request was aborted
 275  * FR_INTERRUPTED:      the request has been interrupted
 276  * FR_LOCKED:           data is being copied to/from the request
 277  * FR_PENDING:          request is not yet in userspace
 278  * FR_SENT:             request is in userspace, waiting for an answer
 279  * FR_FINISHED:         request is finished
 280  * FR_PRIVATE:          request is on private list
 281  */
 282 enum fuse_req_flag {
 283         FR_ISREPLY,
 284         FR_FORCE,
 285         FR_BACKGROUND,
 286         FR_WAITING,
 287         FR_ABORTED,
 288         FR_INTERRUPTED,
 289         FR_LOCKED,
 290         FR_PENDING,
 291         FR_SENT,
 292         FR_FINISHED,
 293         FR_PRIVATE,
 294 };
 295
 296 /**
 297  * A request to the client
 298  *
 299  * .waitq.lock protects the following fields:
 300  *   - FR_ABORTED
 301  *   - FR_LOCKED (may also be modified under fc->lock, tested under both)
 302  */
 303 struct fuse_req {
 304         /** This can be on either pending processing or io lists in
 305             fuse_conn */
 306         struct list_head list;
 307
 308         /** Entry on the interrupts list  */
 309         struct list_head intr_entry;
 310
 311         /** refcount */
 312         refcount_t count;
 313
 314         /** Unique ID for the interrupt request */
 315         u64 intr_unique;
 316
 317         /* Request flags, updated with test/set/clear_bit() */
 318         unsigned long flags;
 319
 320         /** The request input */
 321         struct fuse_in in;
 322
 323         /** The request output */
 324         struct fuse_out out;
 325
 326         /** Used to wake up the task waiting for completion of request*/
 327         wait_queue_head_t waitq;
 328
 329         /** Data for asynchronous requests */
 330         union {
 331                 struct {
 332                         struct fuse_release_in in;
 333                         struct inode *inode;
 334                 } release;
 335                 struct fuse_init_in init_in;
 336                 struct fuse_init_out init_out;
 337                 struct cuse_init_in cuse_init_in;
 338                 struct {
 339                         struct fuse_read_in in;
 340                         u64 attr_ver;
 341                 } read;
 342                 struct {
 343                         struct fuse_write_in in;
 344                         struct fuse_write_out out;
 345                         struct fuse_req *next;
 346                 } write;
 347                 struct fuse_notify_retrieve_in retrieve_in;
 348         } misc;
 349
 350         /** page vector */
 351         struct page **pages;
 352
 353         /** page-descriptor vector */
 354         struct fuse_page_desc *page_descs;
 355
 356         /** size of the 'pages' array */
 357         unsigned max_pages;
 358
 359         /** inline page vector */
 360         struct page *inline_pages[FUSE_REQ_INLINE_PAGES];
 361
 362         /** inline page-descriptor vector */
 363         struct fuse_page_desc inline_page_descs[FUSE_REQ_INLINE_PAGES];
 364
 365         /** number of pages in vector */
 366         unsigned num_pages;
 367
 368         /** File used in the request (or NULL) */
 369         struct fuse_file *ff;
 370
 371         /** Inode used in the request or NULL */
 372         struct inode *inode;
 373
 374         /** AIO control block */
 375         struct fuse_io_priv *io;
 376
 377         /** Link on fi->writepages */
 378         struct list_head writepages_entry;
 379
 380         /** Request completion callback */
 381         void (*end)(struct fuse_conn *, struct fuse_req *);
 382
 383         /** Request is stolen from fuse_file->reserved_req */
 384         struct file *stolen_file;
 385 };
 386
 387 struct fuse_iqueue {
 388         /** Connection established */
 389         unsigned connected;
 390
 391         /** Readers of the connection are waiting on this */
 392         wait_queue_head_t waitq;
 393
 394         /** The next unique request id */
 395         u64 reqctr;
 396
 397         /** The list of pending requests */
 398         struct list_head pending;
 399
 400         /** Pending interrupts */
 401         struct list_head interrupts;
 402
 403         /** Queue of pending forgets */
 404         struct fuse_forget_link forget_list_head;
 405         struct fuse_forget_link *forget_list_tail;
 406
 407         /** Batching of FORGET requests (positive indicates FORGET batch) */
 408         int forget_batch;
 409
 410         /** O_ASYNC requests */
 411         struct fasync_struct *fasync;
 412 };
 413
 414 struct fuse_pqueue {
 415         /** Connection established */
 416         unsigned connected;
 417
 418         /** Lock protecting accessess to  members of this structure */
 419         spinlock_t lock;
 420
 421         /** The list of requests being processed */
 422         struct list_head processing;
 423
 424         /** The list of requests under I/O */
 425         struct list_head io;
 426 };
 427
 428 /**
 429  * Fuse device instance
 430  */
 431 struct fuse_dev {
 432         /** Fuse connection for this device */
 433         struct fuse_conn *fc;
 434
 435         /** Processing queue */
 436         struct fuse_pqueue pq;
 437
 438         /** list entry on fc->devices */
 439         struct list_head entry;
 440 };
 441
 442 /**
 443  * A Fuse connection.
 444  *
 445  * This structure is created, when the filesystem is mounted, and is
 446  * destroyed, when the client device is closed and the filesystem is
 447  * unmounted.
 448  */
 449 struct fuse_conn {
 450         /** Lock protecting accessess to  members of this structure */
 451         spinlock_t lock;
 452
 453         /** Refcount */
 454         refcount_t count;
 455
 456         /** Number of fuse_dev's */
 457         atomic_t dev_count;
 458
 459         struct rcu_head rcu;
 460
 461         /** The user id for this mount */
 462         kuid_t user_id;
 463
 464         /** The group id for this mount */
 465         kgid_t group_id;
 466
 467         /** The pid namespace for this mount */
 468         struct pid_namespace *pid_ns;
 469
 470         /** Maximum read size */
 471         unsigned max_read;
 472
 473         /** Maximum write size */
 474         unsigned max_write;
 475
 476         /** Input queue */
 477         struct fuse_iqueue iq;
 478
 479         /** The next unique kernel file handle */
 480         u64 khctr;
 481
 482         /** rbtree of fuse_files waiting for poll events indexed by ph */
 483         struct rb_root polled_files;
 484
 485         /** Maximum number of outstanding background requests */
 486         unsigned max_background;
 487
 488         /** Number of background requests at which congestion starts */
 489         unsigned congestion_threshold;
 490
 491         /** Number of requests currently in the background */
 492         unsigned num_background;
 493
 494         /** Number of background requests currently queued for userspace */
 495         unsigned active_background;
 496
 497         /** The list of background requests set aside for later queuing */
 498         struct list_head bg_queue;
 499
 500         /** Flag indicating that INIT reply has been received. Allocating
 501          * any fuse request will be suspended until the flag is set */
 502         int initialized;
 503
 504         /** Flag indicating if connection is blocked.  This will be
 505             the case before the INIT reply is received, and if there
 506             are too many outstading backgrounds requests */
 507         int blocked;
 508
 509         /** waitq for blocked connection */
 510         wait_queue_head_t blocked_waitq;
 511
 512         /** waitq for reserved requests */
 513         wait_queue_head_t reserved_req_waitq;
 514
 515         /** Connection established, cleared on umount, connection
 516             abort and device release */
 517         unsigned connected;
 518
 519         /** Connection failed (version mismatch).  Cannot race with
 520             setting other bitfields since it is only set once in INIT
 521             reply, before any other request, and never cleared */
 522         unsigned conn_error:1;
 523
 524         /** Connection successful.  Only set in INIT */
 525         unsigned conn_init:1;
 526
 527         /** Do readpages asynchronously?  Only set in INIT */
 528         unsigned async_read:1;
 529
 530         /** Do not send separate SETATTR request before open(O_TRUNC)  */
 531         unsigned atomic_o_trunc:1;
 532
 533         /** Filesystem supports NFS exporting.  Only set in INIT */
 534         unsigned export_support:1;
 535
 536         /** write-back cache policy (default is write-through) */
 537         unsigned writeback_cache:1;
 538
 539         /** allow parallel lookups and readdir (default is serialized) */
 540         unsigned parallel_dirops:1;
 541
 542         /** handle fs handles killing suid/sgid/cap on write/chown/trunc */
 543         unsigned handle_killpriv:1;
 544
 545         /*
 546          * The following bitfields are only for optimization purposes
 547          * and hence races in setting them will not cause malfunction
 548          */
 549
 550         /** Is open/release not implemented by fs? */
 551         unsigned no_open:1;
 552
 553         /** Is fsync not implemented by fs? */
 554         unsigned no_fsync:1;
 555
 556         /** Is fsyncdir not implemented by fs? */
 557         unsigned no_fsyncdir:1;
 558
 559         /** Is flush not implemented by fs? */
 560         unsigned no_flush:1;
 561
 562         /** Is setxattr not implemented by fs? */
 563         unsigned no_setxattr:1;
 564
 565         /** Is getxattr not implemented by fs? */
 566         unsigned no_getxattr:1;
 567
 568         /** Is listxattr not implemented by fs? */
 569         unsigned no_listxattr:1;
 570
 571         /** Is removexattr not implemented by fs? */
 572         unsigned no_removexattr:1;
 573
 574         /** Are posix file locking primitives not implemented by fs? */
 575         unsigned no_lock:1;
 576
 577         /** Is access not implemented by fs? */
 578         unsigned no_access:1;
 579
 580         /** Is create not implemented by fs? */
 581         unsigned no_create:1;
 582
 583         /** Is interrupt not implemented by fs? */
 584         unsigned no_interrupt:1;
 585
 586         /** Is bmap not implemented by fs? */
 587         unsigned no_bmap:1;
 588
 589         /** Is poll not implemented by fs? */
 590         unsigned no_poll:1;
 591
 592         /** Do multi-page cached writes */
 593         unsigned big_writes:1;
 594
 595         /** Don't apply umask to creation modes */
 596         unsigned dont_mask:1;
 597
 598         /** Are BSD file locking primitives not implemented by fs? */
 599         unsigned no_flock:1;
 600
 601         /** Is fallocate not implemented by fs? */
 602         unsigned no_fallocate:1;
 603
 604         /** Is rename with flags implemented by fs? */
 605         unsigned no_rename2:1;
 606
 607         /** Use enhanced/automatic page cache invalidation. */
 608         unsigned auto_inval_data:1;
 609
 610         /** Does the filesystem support readdirplus? */
 611         unsigned do_readdirplus:1;
 612
 613         /** Does the filesystem want adaptive readdirplus? */
 614         unsigned readdirplus_auto:1;
 615
 616         /** Does the filesystem support asynchronous direct-IO submission? */
 617         unsigned async_dio:1;
 618
 619         /** Is lseek not implemented by fs? */
 620         unsigned no_lseek:1;
 621
 622         /** Does the filesystem support posix acls? */
 623         unsigned posix_acl:1;
 624
 625         /** Check permissions based on the file mode or not? */
 626         unsigned default_permissions:1;
 627
 628         /** Allow other than the mounter user to access the filesystem ? */
 629         unsigned allow_other:1;
 630
 631         /** The number of requests waiting for completion */
 632         atomic_t num_waiting;
 633
 634         /** Negotiated minor version */
 635         unsigned minor;
 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 void fuse_file_free(struct fuse_file *ff);
 736 void fuse_finish_open(struct inode *inode, struct file *file);
 737
 738 void fuse_sync_release(struct fuse_file *ff, int flags);
 739
 740 /**
 741  * Send RELEASE or RELEASEDIR request
 742  */
 743 void fuse_release_common(struct file *file, int opcode);
 744
 745 /**
 746  * Send FSYNC or FSYNCDIR request
 747  */
 748 int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
 749                       int datasync, int isdir);
 750
 751 /**
 752  * Notify poll wakeup
 753  */
 754 int fuse_notify_poll_wakeup(struct fuse_conn *fc,
 755                             struct fuse_notify_poll_wakeup_out *outarg);
 756
 757 /**
 758  * Initialize file operations on a regular file
 759  */
 760 void fuse_init_file_inode(struct inode *inode);
 761
 762 /**
 763  * Initialize inode operations on regular files and special files
 764  */
 765 void fuse_init_common(struct inode *inode);
 766
 767 /**
 768  * Initialize inode and file operations on a directory
 769  */
 770 void fuse_init_dir(struct inode *inode);
 771
 772 /**
 773  * Initialize inode operations on a symlink
 774  */
 775 void fuse_init_symlink(struct inode *inode);
 776
 777 /**
 778  * Change attributes of an inode
 779  */
 780 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
 781                             u64 attr_valid, u64 attr_version);
 782
 783 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
 784                                    u64 attr_valid);
 785
 786 /**
 787  * Initialize the client device
 788  */
 789 int fuse_dev_init(void);
 790
 791 /**
 792  * Cleanup the client device
 793  */
 794 void fuse_dev_cleanup(void);
 795
 796 int fuse_ctl_init(void);
 797 void __exit fuse_ctl_cleanup(void);
 798
 799 /**
 800  * Allocate a request
 801  */
 802 struct fuse_req *fuse_request_alloc(unsigned npages);
 803
 804 struct fuse_req *fuse_request_alloc_nofs(unsigned npages);
 805
 806 /**
 807  * Free a request
 808  */
 809 void fuse_request_free(struct fuse_req *req);
 810
 811 /**
 812  * Get a request, may fail with -ENOMEM,
 813  * caller should specify # elements in req->pages[] explicitly
 814  */
 815 struct fuse_req *fuse_get_req(struct fuse_conn *fc, unsigned npages);
 816 struct fuse_req *fuse_get_req_for_background(struct fuse_conn *fc,
 817                                              unsigned npages);
 818
 819 /*
 820  * Increment reference count on request
 821  */
 822 void __fuse_get_request(struct fuse_req *req);
 823
 824 /**
 825  * Gets a requests for a file operation, always succeeds
 826  */
 827 struct fuse_req *fuse_get_req_nofail_nopages(struct fuse_conn *fc,
 828                                              struct file *file);
 829
 830 /**
 831  * Decrement reference count of a request.  If count goes to zero free
 832  * the request.
 833  */
 834 void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req);
 835
 836 /**
 837  * Send a request (synchronous)
 838  */
 839 void fuse_request_send(struct fuse_conn *fc, struct fuse_req *req);
 840
 841 /**
 842  * Simple request sending that does request allocation and freeing
 843  */
 844 ssize_t fuse_simple_request(struct fuse_conn *fc, struct fuse_args *args);
 845
 846 /**
 847  * Send a request in the background
 848  */
 849 void fuse_request_send_background(struct fuse_conn *fc, struct fuse_req *req);
 850
 851 void fuse_request_send_background_locked(struct fuse_conn *fc,
 852                                          struct fuse_req *req);
 853
 854 /* Abort all requests */
 855 void fuse_abort_conn(struct fuse_conn *fc);
 856
 857 /**
 858  * Invalidate inode attributes
 859  */
 860 void fuse_invalidate_attr(struct inode *inode);
 861
 862 void fuse_invalidate_entry_cache(struct dentry *entry);
 863
 864 void fuse_invalidate_atime(struct inode *inode);
 865
 866 /**
 867  * Acquire reference to fuse_conn
 868  */
 869 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc);
 870
 871 /**
 872  * Initialize fuse_conn
 873  */
 874 void fuse_conn_init(struct fuse_conn *fc);
 875
 876 /**
 877  * Release reference to fuse_conn
 878  */
 879 void fuse_conn_put(struct fuse_conn *fc);
 880
 881 struct fuse_dev *fuse_dev_alloc(struct fuse_conn *fc);
 882 void fuse_dev_free(struct fuse_dev *fud);
 883
 884 /**
 885  * Add connection to control filesystem
 886  */
 887 int fuse_ctl_add_conn(struct fuse_conn *fc);
 888
 889 /**
 890  * Remove connection from control filesystem
 891  */
 892 void fuse_ctl_remove_conn(struct fuse_conn *fc);
 893
 894 /**
 895  * Is file type valid?
 896  */
 897 int fuse_valid_type(int m);
 898
 899 /**
 900  * Is current process allowed to perform filesystem operation?
 901  */
 902 int fuse_allow_current_process(struct fuse_conn *fc);
 903
 904 u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id);
 905
 906 void fuse_update_ctime(struct inode *inode);
 907
 908 int fuse_update_attributes(struct inode *inode, struct kstat *stat,
 909                            struct file *file, bool *refreshed);
 910
 911 void fuse_flush_writepages(struct inode *inode);
 912
 913 void fuse_set_nowrite(struct inode *inode);
 914 void fuse_release_nowrite(struct inode *inode);
 915
 916 u64 fuse_get_attr_version(struct fuse_conn *fc);
 917
 918 /**
 919  * File-system tells the kernel to invalidate cache for the given node id.
 920  */
 921 int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
 922                              loff_t offset, loff_t len);
 923
 924 /**
 925  * File-system tells the kernel to invalidate parent attributes and
 926  * the dentry matching parent/name.
 927  *
 928  * If the child_nodeid is non-zero and:
 929  *    - matches the inode number for the dentry matching parent/name,
 930  *    - is not a mount point
 931  *    - is a file or oan empty directory
 932  * then the dentry is unhashed (d_delete()).
 933  */
 934 int fuse_reverse_inval_entry(struct super_block *sb, u64 parent_nodeid,
 935                              u64 child_nodeid, struct qstr *name);
 936
 937 int fuse_do_open(struct fuse_conn *fc, u64 nodeid, struct file *file,
 938                  bool isdir);
 939
 940 /**
 941  * fuse_direct_io() flags
 942  */
 943
 944 /** If set, it is WRITE; otherwise - READ */
 945 #define FUSE_DIO_WRITE (1 << 0)
 946
 947 /** CUSE pass fuse_direct_io() a file which f_mapping->host is not from FUSE */
 948 #define FUSE_DIO_CUSE  (1 << 1)
 949
 950 ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter,
 951                        loff_t *ppos, int flags);
 952 long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
 953                    unsigned int flags);
 954 long fuse_ioctl_common(struct file *file, unsigned int cmd,
 955                        unsigned long arg, unsigned int flags);
 956 unsigned fuse_file_poll(struct file *file, poll_table *wait);
 957 int fuse_dev_release(struct inode *inode, struct file *file);
 958
 959 bool fuse_write_update_size(struct inode *inode, loff_t pos);
 960
 961 int fuse_flush_times(struct inode *inode, struct fuse_file *ff);
 962 int fuse_write_inode(struct inode *inode, struct writeback_control *wbc);
 963
 964 int fuse_do_setattr(struct dentry *dentry, struct iattr *attr,
 965                     struct file *file);
 966
 967 void fuse_set_initialized(struct fuse_conn *fc);
 968
 969 void fuse_unlock_inode(struct inode *inode);
 970 void fuse_lock_inode(struct inode *inode);
 971
 972 int fuse_setxattr(struct inode *inode, const char *name, const void *value,
 973                   size_t size, int flags);
 974 ssize_t fuse_getxattr(struct inode *inode, const char *name, void *value,
 975                       size_t size);
 976 ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size);
 977 int fuse_removexattr(struct inode *inode, const char *name);
 978 extern const struct xattr_handler *fuse_xattr_handlers[];
 979 extern const struct xattr_handler *fuse_acl_xattr_handlers[];
 980
 981 struct posix_acl;
 982 struct posix_acl *fuse_get_acl(struct inode *inode, int type);
 983 int fuse_set_acl(struct inode *inode, struct posix_acl *acl, int type);
 984
 985 #endif /* _FS_FUSE_I_H */