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 #include <linux/user_namespace.h>
  30
  31 /** Max number of pages that can be used in a single read request */
  32 #define FUSE_MAX_PAGES_PER_REQ 32
  33
  34 /** Bias for fi->writectr, meaning new writepages must not be sent */
  35 #define FUSE_NOWRITE INT_MIN
  36
  37 /** It could be as large as PATH_MAX, but would that have any uses? */
  38 #define FUSE_NAME_MAX 1024
  39
  40 /** Number of dentries for each connection in the control filesystem */
  41 #define FUSE_CTL_NUM_DENTRIES 5
  42
  43 /** Number of page pointers embedded in fuse_req */
  44 #define FUSE_REQ_INLINE_PAGES 1
  45
  46 /** List of active connections */
  47 extern struct list_head fuse_conn_list;
  48
  49 /** Global mutex protecting fuse_conn_list and the control filesystem */
  50 extern struct mutex fuse_mutex;
  51
  52 /** Module parameters */
  53 extern unsigned max_user_bgreq;
  54 extern unsigned max_user_congthresh;
  55
  56 /* One forget request */
  57 struct fuse_forget_link {
  58         struct fuse_forget_one forget_one;
  59         struct fuse_forget_link *next;
  60 };
  61
  62 /** FUSE inode */
  63 struct fuse_inode {
  64         /** Inode data */
  65         struct inode inode;
  66
  67         /** Unique ID, which identifies the inode between userspace
  68          * and kernel */
  69         u64 nodeid;
  70
  71         /** Number of lookups on this inode */
  72         u64 nlookup;
  73
  74         /** The request used for sending the FORGET message */
  75         struct fuse_forget_link *forget;
  76
  77         /** Time in jiffies until the file attributes are valid */
  78         u64 i_time;
  79
  80         /** The sticky bit in inode->i_mode may have been removed, so
  81             preserve the original mode */
  82         umode_t orig_i_mode;
  83
  84         /** 64 bit inode number */
  85         u64 orig_ino;
  86
  87         /** Version of last attribute change */
  88         u64 attr_version;
  89
  90         /** Files usable in writepage.  Protected by fc->lock */
  91         struct list_head write_files;
  92
  93         /** Writepages pending on truncate or fsync */
  94         struct list_head queued_writes;
  95
  96         /** Number of sent writes, a negative bias (FUSE_NOWRITE)
  97          * means more writes are blocked */
  98         int writectr;
  99
 100         /** Waitq for writepage completion */
 101         wait_queue_head_t page_waitq;
 102
 103         /** List of writepage requestst (pending or sent) */
 104         struct list_head writepages;
 105
 106         /** Miscellaneous bits describing inode state */
 107         unsigned long state;
 108
 109         /** Lock for serializing lookup and readdir for back compatibility*/
 110         struct mutex mutex;
 111 };
 112
 113 /** FUSE inode state bits */
 114 enum {
 115         /** Advise readdirplus  */
 116         FUSE_I_ADVISE_RDPLUS,
 117         /** Initialized with readdirplus */
 118         FUSE_I_INIT_RDPLUS,
 119         /** An operation changing file size is in progress  */
 120         FUSE_I_SIZE_UNSTABLE,
 121 };
 122
 123 struct fuse_conn;
 124
 125 /** FUSE specific file data */
 126 struct fuse_file {
 127         /** Fuse connection for this file */
 128         struct fuse_conn *fc;
 129
 130         /** Request reserved for flush and release */
 131         struct fuse_req *reserved_req;
 132
 133         /** Kernel file handle guaranteed to be unique */
 134         u64 kh;
 135
 136         /** File handle used by userspace */
 137         u64 fh;
 138
 139         /** Node id of this file */
 140         u64 nodeid;
 141
 142         /** Refcount */
 143         refcount_t count;
 144
 145         /** FOPEN_* flags returned by open */
 146         u32 open_flags;
 147
 148         /** Entry on inode's write_files list */
 149         struct list_head write_entry;
 150
 151         /** RB node to be linked on fuse_conn->polled_files */
 152         struct rb_node polled_node;
 153
 154         /** Wait queue head for poll */
 155         wait_queue_head_t poll_wait;
 156
 157         /** Has flock been performed on this file? */
 158         bool flock:1;
 159 };
 160
 161 /** One input argument of a request */
 162 struct fuse_in_arg {
 163         unsigned size;
 164         const void *value;
 165 };
 166
 167 /** The request input */
 168 struct fuse_in {
 169         /** The request header */
 170         struct fuse_in_header h;
 171
 172         /** True if the data for the last argument is in req->pages */
 173         unsigned argpages:1;
 174
 175         /** Number of arguments */
 176         unsigned numargs;
 177
 178         /** Array of arguments */
 179         struct fuse_in_arg args[3];
 180 };
 181
 182 /** One output argument of a request */
 183 struct fuse_arg {
 184         unsigned size;
 185         void *value;
 186 };
 187
 188 /** The request output */
 189 struct fuse_out {
 190         /** Header returned from userspace */
 191         struct fuse_out_header h;
 192
 193         /*
 194          * The following bitfields are not changed during the request
 195          * processing
 196          */
 197
 198         /** Last argument is variable length (can be shorter than
 199             arg->size) */
 200         unsigned argvar:1;
 201
 202         /** Last argument is a list of pages to copy data to */
 203         unsigned argpages:1;
 204
 205         /** Zero partially or not copied pages */
 206         unsigned page_zeroing:1;
 207
 208         /** Pages may be replaced with new ones */
 209         unsigned page_replace:1;
 210
 211         /** Number or arguments */
 212         unsigned numargs;
 213
 214         /** Array of arguments */
 215         struct fuse_arg args[2];
 216 };
 217
 218 /** FUSE page descriptor */
 219 struct fuse_page_desc {
 220         unsigned int length;
 221         unsigned int offset;
 222 };
 223
 224 struct fuse_args {
 225         struct {
 226                 struct {
 227                         uint32_t opcode;
 228                         uint64_t nodeid;
 229                 } h;
 230                 unsigned numargs;
 231                 struct fuse_in_arg args[3];
 232
 233         } in;
 234         struct {
 235                 unsigned argvar:1;
 236                 unsigned numargs;
 237                 struct fuse_arg args[2];
 238         } out;
 239 };
 240
 241 #define FUSE_ARGS(args) struct fuse_args args = {}
 242
 243 /** The request IO state (for asynchronous processing) */
 244 struct fuse_io_priv {
 245         struct kref refcnt;
 246         int async;
 247         spinlock_t lock;
 248         unsigned reqs;
 249         ssize_t bytes;
 250         size_t size;
 251         __u64 offset;
 252         bool write;
 253         bool should_dirty;
 254         int err;
 255         struct kiocb *iocb;
 256         struct completion *done;
 257         bool blocking;
 258 };
 259
 260 #define FUSE_IO_PRIV_SYNC(i) \
 261 {                                       \
 262         .refcnt = KREF_INIT(1),         \
 263         .async = 0,                     \
 264         .iocb = i,                      \
 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         /** The user namespace for this mount */
 471         struct user_namespace *user_ns;
 472
 473         /** Maximum read size */
 474         unsigned max_read;
 475
 476         /** Maximum write size */
 477         unsigned max_write;
 478
 479         /** Input queue */
 480         struct fuse_iqueue iq;
 481
 482         /** The next unique kernel file handle */
 483         u64 khctr;
 484
 485         /** rbtree of fuse_files waiting for poll events indexed by ph */
 486         struct rb_root polled_files;
 487
 488         /** Maximum number of outstanding background requests */
 489         unsigned max_background;
 490
 491         /** Number of background requests at which congestion starts */
 492         unsigned congestion_threshold;
 493
 494         /** Number of requests currently in the background */
 495         unsigned num_background;
 496
 497         /** Number of background requests currently queued for userspace */
 498         unsigned active_background;
 499
 500         /** The list of background requests set aside for later queuing */
 501         struct list_head bg_queue;
 502
 503         /** Flag indicating that INIT reply has been received. Allocating
 504          * any fuse request will be suspended until the flag is set */
 505         int initialized;
 506
 507         /** Flag indicating if connection is blocked.  This will be
 508             the case before the INIT reply is received, and if there
 509             are too many outstading backgrounds requests */
 510         int blocked;
 511
 512         /** waitq for blocked connection */
 513         wait_queue_head_t blocked_waitq;
 514
 515         /** waitq for reserved requests */
 516         wait_queue_head_t reserved_req_waitq;
 517
 518         /** Connection established, cleared on umount, connection
 519             abort and device release */
 520         unsigned connected;
 521
 522         /** Connection failed (version mismatch).  Cannot race with
 523             setting other bitfields since it is only set once in INIT
 524             reply, before any other request, and never cleared */
 525         unsigned conn_error:1;
 526
 527         /** Connection successful.  Only set in INIT */
 528         unsigned conn_init:1;
 529
 530         /** Do readpages asynchronously?  Only set in INIT */
 531         unsigned async_read:1;
 532
 533         /** Do not send separate SETATTR request before open(O_TRUNC)  */
 534         unsigned atomic_o_trunc:1;
 535
 536         /** Filesystem supports NFS exporting.  Only set in INIT */
 537         unsigned export_support:1;
 538
 539         /** write-back cache policy (default is write-through) */
 540         unsigned writeback_cache:1;
 541
 542         /** allow parallel lookups and readdir (default is serialized) */
 543         unsigned parallel_dirops:1;
 544
 545         /** handle fs handles killing suid/sgid/cap on write/chown/trunc */
 546         unsigned handle_killpriv:1;
 547
 548         /*
 549          * The following bitfields are only for optimization purposes
 550          * and hence races in setting them will not cause malfunction
 551          */
 552
 553         /** Is open/release not implemented by fs? */
 554         unsigned no_open:1;
 555
 556         /** Is fsync not implemented by fs? */
 557         unsigned no_fsync:1;
 558
 559         /** Is fsyncdir not implemented by fs? */
 560         unsigned no_fsyncdir:1;
 561
 562         /** Is flush not implemented by fs? */
 563         unsigned no_flush:1;
 564
 565         /** Is setxattr not implemented by fs? */
 566         unsigned no_setxattr:1;
 567
 568         /** Is getxattr not implemented by fs? */
 569         unsigned no_getxattr:1;
 570
 571         /** Is listxattr not implemented by fs? */
 572         unsigned no_listxattr:1;
 573
 574         /** Is removexattr not implemented by fs? */
 575         unsigned no_removexattr:1;
 576
 577         /** Are posix file locking primitives not implemented by fs? */
 578         unsigned no_lock:1;
 579
 580         /** Is access not implemented by fs? */
 581         unsigned no_access:1;
 582
 583         /** Is create not implemented by fs? */
 584         unsigned no_create:1;
 585
 586         /** Is interrupt not implemented by fs? */
 587         unsigned no_interrupt:1;
 588
 589         /** Is bmap not implemented by fs? */
 590         unsigned no_bmap:1;
 591
 592         /** Is poll not implemented by fs? */
 593         unsigned no_poll:1;
 594
 595         /** Do multi-page cached writes */
 596         unsigned big_writes:1;
 597
 598         /** Don't apply umask to creation modes */
 599         unsigned dont_mask:1;
 600
 601         /** Are BSD file locking primitives not implemented by fs? */
 602         unsigned no_flock:1;
 603
 604         /** Is fallocate not implemented by fs? */
 605         unsigned no_fallocate:1;
 606
 607         /** Is rename with flags implemented by fs? */
 608         unsigned no_rename2:1;
 609
 610         /** Use enhanced/automatic page cache invalidation. */
 611         unsigned auto_inval_data:1;
 612
 613         /** Does the filesystem support readdirplus? */
 614         unsigned do_readdirplus:1;
 615
 616         /** Does the filesystem want adaptive readdirplus? */
 617         unsigned readdirplus_auto:1;
 618
 619         /** Does the filesystem support asynchronous direct-IO submission? */
 620         unsigned async_dio:1;
 621
 622         /** Is lseek not implemented by fs? */
 623         unsigned no_lseek:1;
 624
 625         /** Does the filesystem support posix acls? */
 626         unsigned posix_acl:1;
 627
 628         /** Check permissions based on the file mode or not? */
 629         unsigned default_permissions:1;
 630
 631         /** Allow other than the mounter user to access the filesystem ? */
 632         unsigned allow_other: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         /** Entry on the fuse_conn_list */
 641         struct list_head entry;
 642
 643         /** Device ID from super block */
 644         dev_t dev;
 645
 646         /** Dentries in the control filesystem */
 647         struct dentry *ctl_dentry[FUSE_CTL_NUM_DENTRIES];
 648
 649         /** number of dentries used in the above array */
 650         int ctl_ndents;
 651
 652         /** Key for lock owner ID scrambling */
 653         u32 scramble_key[4];
 654
 655         /** Reserved request for the DESTROY message */
 656         struct fuse_req *destroy_req;
 657
 658         /** Version counter for attribute changes */
 659         u64 attr_version;
 660
 661         /** Called on final put */
 662         void (*release)(struct fuse_conn *);
 663
 664         /** Super block for this connection. */
 665         struct super_block *sb;
 666
 667         /** Read/write semaphore to hold when accessing sb. */
 668         struct rw_semaphore killsb;
 669
 670         /** List of device instances belonging to this connection */
 671         struct list_head devices;
 672 };
 673
 674 static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
 675 {
 676         return sb->s_fs_info;
 677 }
 678
 679 static inline struct fuse_conn *get_fuse_conn(struct inode *inode)
 680 {
 681         return get_fuse_conn_super(inode->i_sb);
 682 }
 683
 684 static inline struct fuse_inode *get_fuse_inode(struct inode *inode)
 685 {
 686         return container_of(inode, struct fuse_inode, inode);
 687 }
 688
 689 static inline u64 get_node_id(struct inode *inode)
 690 {
 691         return get_fuse_inode(inode)->nodeid;
 692 }
 693
 694 /** Device operations */
 695 extern const struct file_operations fuse_dev_operations;
 696
 697 extern const struct dentry_operations fuse_dentry_operations;
 698 extern const struct dentry_operations fuse_root_dentry_operations;
 699
 700 /**
 701  * Inode to nodeid comparison.
 702  */
 703 int fuse_inode_eq(struct inode *inode, void *_nodeidp);
 704
 705 /**
 706  * Get a filled in inode
 707  */
 708 struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
 709                         int generation, struct fuse_attr *attr,
 710                         u64 attr_valid, u64 attr_version);
 711
 712 int fuse_lookup_name(struct super_block *sb, u64 nodeid, const struct qstr *name,
 713                      struct fuse_entry_out *outarg, struct inode **inode);
 714
 715 /**
 716  * Send FORGET command
 717  */
 718 void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget,
 719                        u64 nodeid, u64 nlookup);
 720
 721 struct fuse_forget_link *fuse_alloc_forget(void);
 722
 723 /* Used by READDIRPLUS */
 724 void fuse_force_forget(struct file *file, u64 nodeid);
 725
 726 /**
 727  * Initialize READ or READDIR request
 728  */
 729 void fuse_read_fill(struct fuse_req *req, struct file *file,
 730                     loff_t pos, size_t count, int opcode);
 731
 732 /**
 733  * Send OPEN or OPENDIR request
 734  */
 735 int fuse_open_common(struct inode *inode, struct file *file, bool isdir);
 736
 737 struct fuse_file *fuse_file_alloc(struct fuse_conn *fc);
 738 void fuse_file_free(struct fuse_file *ff);
 739 void fuse_finish_open(struct inode *inode, struct file *file);
 740
 741 void fuse_sync_release(struct fuse_file *ff, int flags);
 742
 743 /**
 744  * Send RELEASE or RELEASEDIR request
 745  */
 746 void fuse_release_common(struct file *file, int opcode);
 747
 748 /**
 749  * Send FSYNC or FSYNCDIR request
 750  */
 751 int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
 752                       int datasync, int isdir);
 753
 754 /**
 755  * Notify poll wakeup
 756  */
 757 int fuse_notify_poll_wakeup(struct fuse_conn *fc,
 758                             struct fuse_notify_poll_wakeup_out *outarg);
 759
 760 /**
 761  * Initialize file operations on a regular file
 762  */
 763 void fuse_init_file_inode(struct inode *inode);
 764
 765 /**
 766  * Initialize inode operations on regular files and special files
 767  */
 768 void fuse_init_common(struct inode *inode);
 769
 770 /**
 771  * Initialize inode and file operations on a directory
 772  */
 773 void fuse_init_dir(struct inode *inode);
 774
 775 /**
 776  * Initialize inode operations on a symlink
 777  */
 778 void fuse_init_symlink(struct inode *inode);
 779
 780 /**
 781  * Change attributes of an inode
 782  */
 783 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
 784                             u64 attr_valid, u64 attr_version);
 785
 786 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
 787                                    u64 attr_valid);
 788
 789 /**
 790  * Initialize the client device
 791  */
 792 int fuse_dev_init(void);
 793
 794 /**
 795  * Cleanup the client device
 796  */
 797 void fuse_dev_cleanup(void);
 798
 799 int fuse_ctl_init(void);
 800 void __exit fuse_ctl_cleanup(void);
 801
 802 /**
 803  * Allocate a request
 804  */
 805 struct fuse_req *fuse_request_alloc(unsigned npages);
 806
 807 struct fuse_req *fuse_request_alloc_nofs(unsigned npages);
 808
 809 /**
 810  * Free a request
 811  */
 812 void fuse_request_free(struct fuse_req *req);
 813
 814 /**
 815  * Get a request, may fail with -ENOMEM,
 816  * caller should specify # elements in req->pages[] explicitly
 817  */
 818 struct fuse_req *fuse_get_req(struct fuse_conn *fc, unsigned npages);
 819 struct fuse_req *fuse_get_req_for_background(struct fuse_conn *fc,
 820                                              unsigned npages);
 821
 822 /*
 823  * Increment reference count on request
 824  */
 825 void __fuse_get_request(struct fuse_req *req);
 826
 827 /**
 828  * Gets a requests for a file operation, always succeeds
 829  */
 830 struct fuse_req *fuse_get_req_nofail_nopages(struct fuse_conn *fc,
 831                                              struct file *file);
 832
 833 /**
 834  * Decrement reference count of a request.  If count goes to zero free
 835  * the request.
 836  */
 837 void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req);
 838
 839 /**
 840  * Send a request (synchronous)
 841  */
 842 void fuse_request_send(struct fuse_conn *fc, struct fuse_req *req);
 843
 844 /**
 845  * Simple request sending that does request allocation and freeing
 846  */
 847 ssize_t fuse_simple_request(struct fuse_conn *fc, struct fuse_args *args);
 848
 849 /**
 850  * Send a request in the background
 851  */
 852 void fuse_request_send_background(struct fuse_conn *fc, struct fuse_req *req);
 853
 854 void fuse_request_send_background_locked(struct fuse_conn *fc,
 855                                          struct fuse_req *req);
 856
 857 /* Abort all requests */
 858 void fuse_abort_conn(struct fuse_conn *fc);
 859 void fuse_wait_aborted(struct fuse_conn *fc);
 860
 861 /**
 862  * Invalidate inode attributes
 863  */
 864 void fuse_invalidate_attr(struct inode *inode);
 865
 866 void fuse_invalidate_entry_cache(struct dentry *entry);
 867
 868 void fuse_invalidate_atime(struct inode *inode);
 869
 870 /**
 871  * Acquire reference to fuse_conn
 872  */
 873 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc);
 874
 875 /**
 876  * Initialize fuse_conn
 877  */
 878 void fuse_conn_init(struct fuse_conn *fc, struct user_namespace *user_ns);
 879
 880 /**
 881  * Release reference to fuse_conn
 882  */
 883 void fuse_conn_put(struct fuse_conn *fc);
 884
 885 struct fuse_dev *fuse_dev_alloc(struct fuse_conn *fc);
 886 void fuse_dev_free(struct fuse_dev *fud);
 887
 888 /**
 889  * Add connection to control filesystem
 890  */
 891 int fuse_ctl_add_conn(struct fuse_conn *fc);
 892
 893 /**
 894  * Remove connection from control filesystem
 895  */
 896 void fuse_ctl_remove_conn(struct fuse_conn *fc);
 897
 898 /**
 899  * Is file type valid?
 900  */
 901 int fuse_valid_type(int m);
 902
 903 /**
 904  * Is current process allowed to perform filesystem operation?
 905  */
 906 int fuse_allow_current_process(struct fuse_conn *fc);
 907
 908 u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id);
 909
 910 void fuse_update_ctime(struct inode *inode);
 911
 912 int fuse_update_attributes(struct inode *inode, struct file *file);
 913
 914 void fuse_flush_writepages(struct inode *inode);
 915
 916 void fuse_set_nowrite(struct inode *inode);
 917 void fuse_release_nowrite(struct inode *inode);
 918
 919 u64 fuse_get_attr_version(struct fuse_conn *fc);
 920
 921 /**
 922  * File-system tells the kernel to invalidate cache for the given node id.
 923  */
 924 int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
 925                              loff_t offset, loff_t len);
 926
 927 /**
 928  * File-system tells the kernel to invalidate parent attributes and
 929  * the dentry matching parent/name.
 930  *
 931  * If the child_nodeid is non-zero and:
 932  *    - matches the inode number for the dentry matching parent/name,
 933  *    - is not a mount point
 934  *    - is a file or oan empty directory
 935  * then the dentry is unhashed (d_delete()).
 936  */
 937 int fuse_reverse_inval_entry(struct super_block *sb, u64 parent_nodeid,
 938                              u64 child_nodeid, struct qstr *name);
 939
 940 int fuse_do_open(struct fuse_conn *fc, u64 nodeid, struct file *file,
 941                  bool isdir);
 942
 943 /**
 944  * fuse_direct_io() flags
 945  */
 946
 947 /** If set, it is WRITE; otherwise - READ */
 948 #define FUSE_DIO_WRITE (1 << 0)
 949
 950 /** CUSE pass fuse_direct_io() a file which f_mapping->host is not from FUSE */
 951 #define FUSE_DIO_CUSE  (1 << 1)
 952
 953 ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter,
 954                        loff_t *ppos, int flags);
 955 long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
 956                    unsigned int flags);
 957 long fuse_ioctl_common(struct file *file, unsigned int cmd,
 958                        unsigned long arg, unsigned int flags);
 959 unsigned fuse_file_poll(struct file *file, poll_table *wait);
 960 int fuse_dev_release(struct inode *inode, struct file *file);
 961
 962 bool fuse_write_update_size(struct inode *inode, loff_t pos);
 963
 964 int fuse_flush_times(struct inode *inode, struct fuse_file *ff);
 965 int fuse_write_inode(struct inode *inode, struct writeback_control *wbc);
 966
 967 int fuse_do_setattr(struct dentry *dentry, struct iattr *attr,
 968                     struct file *file);
 969
 970 void fuse_set_initialized(struct fuse_conn *fc);
 971
 972 void fuse_unlock_inode(struct inode *inode, bool locked);
 973 bool fuse_lock_inode(struct inode *inode);
 974
 975 int fuse_setxattr(struct inode *inode, const char *name, const void *value,
 976                   size_t size, int flags);
 977 ssize_t fuse_getxattr(struct inode *inode, const char *name, void *value,
 978                       size_t size);
 979 ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size);
 980 int fuse_removexattr(struct inode *inode, const char *name);
 981 extern const struct xattr_handler *fuse_xattr_handlers[];
 982 extern const struct xattr_handler *fuse_acl_xattr_handlers[];
 983
 984 struct posix_acl;
 985 struct posix_acl *fuse_get_acl(struct inode *inode, int type);
 986 int fuse_set_acl(struct inode *inode, struct posix_acl *acl, int type);
 987
 988 #endif /* _FS_FUSE_I_H */