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 #ifndef pr_fmt
  13 # define pr_fmt(fmt) "fuse: " fmt
  14 #endif
  15
  16 #include <linux/fuse.h>
  17 #include <linux/fs.h>
  18 #include <linux/mount.h>
  19 #include <linux/wait.h>
  20 #include <linux/list.h>
  21 #include <linux/spinlock.h>
  22 #include <linux/mm.h>
  23 #include <linux/backing-dev.h>
  24 #include <linux/mutex.h>
  25 #include <linux/rwsem.h>
  26 #include <linux/rbtree.h>
  27 #include <linux/poll.h>
  28 #include <linux/workqueue.h>
  29 #include <linux/kref.h>
  30 #include <linux/xattr.h>
  31 #include <linux/pid_namespace.h>
  32 #include <linux/refcount.h>
  33 #include <linux/user_namespace.h>
  34
  35 /** Default max number of pages that can be used in a single read request */
  36 #define FUSE_DEFAULT_MAX_PAGES_PER_REQ 32
  37
  38 /** Maximum of max_pages received in init_out */
  39 #define FUSE_MAX_MAX_PAGES 256
  40
  41 /** Bias for fi->writectr, meaning new writepages must not be sent */
  42 #define FUSE_NOWRITE INT_MIN
  43
  44 /** It could be as large as PATH_MAX, but would that have any uses? */
  45 #define FUSE_NAME_MAX 1024
  46
  47 /** Number of dentries for each connection in the control filesystem */
  48 #define FUSE_CTL_NUM_DENTRIES 5
  49
  50 /** List of active connections */
  51 extern struct list_head fuse_conn_list;
  52
  53 /** Global mutex protecting fuse_conn_list and the control filesystem */
  54 extern struct mutex fuse_mutex;
  55
  56 /** Module parameters */
  57 extern unsigned max_user_bgreq;
  58 extern unsigned max_user_congthresh;
  59
  60 /* One forget request */
  61 struct fuse_forget_link {
  62         struct fuse_forget_one forget_one;
  63         struct fuse_forget_link *next;
  64 };
  65
  66 /** FUSE inode */
  67 struct fuse_inode {
  68         /** Inode data */
  69         struct inode inode;
  70
  71         /** Unique ID, which identifies the inode between userspace
  72          * and kernel */
  73         u64 nodeid;
  74
  75         /** Number of lookups on this inode */
  76         u64 nlookup;
  77
  78         /** The request used for sending the FORGET message */
  79         struct fuse_forget_link *forget;
  80
  81         /** Time in jiffies until the file attributes are valid */
  82         u64 i_time;
  83
  84         /* Which attributes are invalid */
  85         u32 inval_mask;
  86
  87         /** The sticky bit in inode->i_mode may have been removed, so
  88             preserve the original mode */
  89         umode_t orig_i_mode;
  90
  91         /** 64 bit inode number */
  92         u64 orig_ino;
  93
  94         /** Version of last attribute change */
  95         u64 attr_version;
  96
  97         union {
  98                 /* Write related fields (regular file only) */
  99                 struct {
 100                         /* Files usable in writepage.  Protected by fi->lock */
 101                         struct list_head write_files;
 102
 103                         /* Writepages pending on truncate or fsync */
 104                         struct list_head queued_writes;
 105
 106                         /* Number of sent writes, a negative bias
 107                          * (FUSE_NOWRITE) means more writes are blocked */
 108                         int writectr;
 109
 110                         /* Waitq for writepage completion */
 111                         wait_queue_head_t page_waitq;
 112
 113                         /* List of writepage requestst (pending or sent) */
 114                         struct list_head writepages;
 115                 };
 116
 117                 /* readdir cache (directory only) */
 118                 struct {
 119                         /* true if fully cached */
 120                         bool cached;
 121
 122                         /* size of cache */
 123                         loff_t size;
 124
 125                         /* position at end of cache (position of next entry) */
 126                         loff_t pos;
 127
 128                         /* version of the cache */
 129                         u64 version;
 130
 131                         /* modification time of directory when cache was
 132                          * started */
 133                         struct timespec64 mtime;
 134
 135                         /* iversion of directory when cache was started */
 136                         u64 iversion;
 137
 138                         /* protects above fields */
 139                         spinlock_t lock;
 140                 } rdc;
 141         };
 142
 143         /** Miscellaneous bits describing inode state */
 144         unsigned long state;
 145
 146         /** Lock for serializing lookup and readdir for back compatibility*/
 147         struct mutex mutex;
 148
 149         /** Lock to protect write related fields */
 150         spinlock_t lock;
 151 };
 152
 153 /** FUSE inode state bits */
 154 enum {
 155         /** Advise readdirplus  */
 156         FUSE_I_ADVISE_RDPLUS,
 157         /** Initialized with readdirplus */
 158         FUSE_I_INIT_RDPLUS,
 159         /** An operation changing file size is in progress  */
 160         FUSE_I_SIZE_UNSTABLE,
 161 };
 162
 163 struct fuse_conn;
 164 struct fuse_release_args;
 165
 166 /** FUSE specific file data */
 167 struct fuse_file {
 168         /** Fuse connection for this file */
 169         struct fuse_conn *fc;
 170
 171         /* Argument space reserved for release */
 172         struct fuse_release_args *release_args;
 173
 174         /** Kernel file handle guaranteed to be unique */
 175         u64 kh;
 176
 177         /** File handle used by userspace */
 178         u64 fh;
 179
 180         /** Node id of this file */
 181         u64 nodeid;
 182
 183         /** Refcount */
 184         refcount_t count;
 185
 186         /** FOPEN_* flags returned by open */
 187         u32 open_flags;
 188
 189         /** Entry on inode's write_files list */
 190         struct list_head write_entry;
 191
 192         /* Readdir related */
 193         struct {
 194                 /*
 195                  * Protects below fields against (crazy) parallel readdir on
 196                  * same open file.  Uncontended in the normal case.
 197                  */
 198                 struct mutex lock;
 199
 200                 /* Dir stream position */
 201                 loff_t pos;
 202
 203                 /* Offset in cache */
 204                 loff_t cache_off;
 205
 206                 /* Version of cache we are reading */
 207                 u64 version;
 208
 209         } readdir;
 210
 211         /** RB node to be linked on fuse_conn->polled_files */
 212         struct rb_node polled_node;
 213
 214         /** Wait queue head for poll */
 215         wait_queue_head_t poll_wait;
 216
 217         /** Has flock been performed on this file? */
 218         bool flock:1;
 219 };
 220
 221 /** One input argument of a request */
 222 struct fuse_in_arg {
 223         unsigned size;
 224         const void *value;
 225 };
 226
 227 /** One output argument of a request */
 228 struct fuse_arg {
 229         unsigned size;
 230         void *value;
 231 };
 232
 233 /** FUSE page descriptor */
 234 struct fuse_page_desc {
 235         unsigned int length;
 236         unsigned int offset;
 237 };
 238
 239 struct fuse_args {
 240         uint64_t nodeid;
 241         uint32_t opcode;
 242         unsigned short in_numargs;
 243         unsigned short out_numargs;
 244         bool force:1;
 245         bool noreply:1;
 246         bool nocreds:1;
 247         bool in_pages:1;
 248         bool out_pages:1;
 249         bool out_argvar:1;
 250         bool page_zeroing:1;
 251         bool page_replace:1;
 252         bool may_block:1;
 253         struct fuse_in_arg in_args[3];
 254         struct fuse_arg out_args[2];
 255         void (*end)(struct fuse_conn *fc, struct fuse_args *args, int error);
 256 };
 257
 258 struct fuse_args_pages {
 259         struct fuse_args args;
 260         struct page **pages;
 261         struct fuse_page_desc *descs;
 262         unsigned int num_pages;
 263 };
 264
 265 #define FUSE_ARGS(args) struct fuse_args args = {}
 266
 267 /** The request IO state (for asynchronous processing) */
 268 struct fuse_io_priv {
 269         struct kref refcnt;
 270         int async;
 271         spinlock_t lock;
 272         unsigned reqs;
 273         ssize_t bytes;
 274         size_t size;
 275         __u64 offset;
 276         bool write;
 277         bool should_dirty;
 278         int err;
 279         struct kiocb *iocb;
 280         struct completion *done;
 281         bool blocking;
 282 };
 283
 284 #define FUSE_IO_PRIV_SYNC(i) \
 285 {                                       \
 286         .refcnt = KREF_INIT(1),         \
 287         .async = 0,                     \
 288         .iocb = i,                      \
 289 }
 290
 291 /**
 292  * Request flags
 293  *
 294  * FR_ISREPLY:          set if the request has reply
 295  * FR_FORCE:            force sending of the request even if interrupted
 296  * FR_BACKGROUND:       request is sent in the background
 297  * FR_WAITING:          request is counted as "waiting"
 298  * FR_ABORTED:          the request was aborted
 299  * FR_INTERRUPTED:      the request has been interrupted
 300  * FR_LOCKED:           data is being copied to/from the request
 301  * FR_PENDING:          request is not yet in userspace
 302  * FR_SENT:             request is in userspace, waiting for an answer
 303  * FR_FINISHED:         request is finished
 304  * FR_PRIVATE:          request is on private list
 305  * FR_ASYNC:            request is asynchronous
 306  */
 307 enum fuse_req_flag {
 308         FR_ISREPLY,
 309         FR_FORCE,
 310         FR_BACKGROUND,
 311         FR_WAITING,
 312         FR_ABORTED,
 313         FR_INTERRUPTED,
 314         FR_LOCKED,
 315         FR_PENDING,
 316         FR_SENT,
 317         FR_FINISHED,
 318         FR_PRIVATE,
 319         FR_ASYNC,
 320 };
 321
 322 /**
 323  * A request to the client
 324  *
 325  * .waitq.lock protects the following fields:
 326  *   - FR_ABORTED
 327  *   - FR_LOCKED (may also be modified under fc->lock, tested under both)
 328  */
 329 struct fuse_req {
 330         /** This can be on either pending processing or io lists in
 331             fuse_conn */
 332         struct list_head list;
 333
 334         /** Entry on the interrupts list  */
 335         struct list_head intr_entry;
 336
 337         /* Input/output arguments */
 338         struct fuse_args *args;
 339
 340         /** refcount */
 341         refcount_t count;
 342
 343         /* Request flags, updated with test/set/clear_bit() */
 344         unsigned long flags;
 345
 346         /* The request input header */
 347         struct {
 348                 struct fuse_in_header h;
 349         } in;
 350
 351         /* The request output header */
 352         struct {
 353                 struct fuse_out_header h;
 354         } out;
 355
 356         /** Used to wake up the task waiting for completion of request*/
 357         wait_queue_head_t waitq;
 358
 359 #if IS_ENABLED(CONFIG_VIRTIO_FS)
 360         /** virtio-fs's physically contiguous buffer for in and out args */
 361         void *argbuf;
 362 #endif
 363 };
 364
 365 struct fuse_iqueue;
 366
 367 /**
 368  * Input queue callbacks
 369  *
 370  * Input queue signalling is device-specific.  For example, the /dev/fuse file
 371  * uses fiq->waitq and fasync to wake processes that are waiting on queue
 372  * readiness.  These callbacks allow other device types to respond to input
 373  * queue activity.
 374  */
 375 struct fuse_iqueue_ops {
 376         /**
 377          * Signal that a forget has been queued
 378          */
 379         void (*wake_forget_and_unlock)(struct fuse_iqueue *fiq)
 380                 __releases(fiq->lock);
 381
 382         /**
 383          * Signal that an INTERRUPT request has been queued
 384          */
 385         void (*wake_interrupt_and_unlock)(struct fuse_iqueue *fiq)
 386                 __releases(fiq->lock);
 387
 388         /**
 389          * Signal that a request has been queued
 390          */
 391         void (*wake_pending_and_unlock)(struct fuse_iqueue *fiq)
 392                 __releases(fiq->lock);
 393
 394         /**
 395          * Clean up when fuse_iqueue is destroyed
 396          */
 397         void (*release)(struct fuse_iqueue *fiq);
 398 };
 399
 400 /** /dev/fuse input queue operations */
 401 extern const struct fuse_iqueue_ops fuse_dev_fiq_ops;
 402
 403 struct fuse_iqueue {
 404         /** Connection established */
 405         unsigned connected;
 406
 407         /** Lock protecting accesses to members of this structure */
 408         spinlock_t lock;
 409
 410         /** Readers of the connection are waiting on this */
 411         wait_queue_head_t waitq;
 412
 413         /** The next unique request id */
 414         u64 reqctr;
 415
 416         /** The list of pending requests */
 417         struct list_head pending;
 418
 419         /** Pending interrupts */
 420         struct list_head interrupts;
 421
 422         /** Queue of pending forgets */
 423         struct fuse_forget_link forget_list_head;
 424         struct fuse_forget_link *forget_list_tail;
 425
 426         /** Batching of FORGET requests (positive indicates FORGET batch) */
 427         int forget_batch;
 428
 429         /** O_ASYNC requests */
 430         struct fasync_struct *fasync;
 431
 432         /** Device-specific callbacks */
 433         const struct fuse_iqueue_ops *ops;
 434
 435         /** Device-specific state */
 436         void *priv;
 437 };
 438
 439 #define FUSE_PQ_HASH_BITS 8
 440 #define FUSE_PQ_HASH_SIZE (1 << FUSE_PQ_HASH_BITS)
 441
 442 struct fuse_pqueue {
 443         /** Connection established */
 444         unsigned connected;
 445
 446         /** Lock protecting accessess to  members of this structure */
 447         spinlock_t lock;
 448
 449         /** Hash table of requests being processed */
 450         struct list_head *processing;
 451
 452         /** The list of requests under I/O */
 453         struct list_head io;
 454 };
 455
 456 /**
 457  * Fuse device instance
 458  */
 459 struct fuse_dev {
 460         /** Fuse connection for this device */
 461         struct fuse_conn *fc;
 462
 463         /** Processing queue */
 464         struct fuse_pqueue pq;
 465
 466         /** list entry on fc->devices */
 467         struct list_head entry;
 468 };
 469
 470 struct fuse_fs_context {
 471         int fd;
 472         unsigned int rootmode;
 473         kuid_t user_id;
 474         kgid_t group_id;
 475         bool is_bdev:1;
 476         bool fd_present:1;
 477         bool rootmode_present:1;
 478         bool user_id_present:1;
 479         bool group_id_present:1;
 480         bool default_permissions:1;
 481         bool allow_other:1;
 482         bool destroy:1;
 483         bool no_control:1;
 484         bool no_force_umount:1;
 485         bool no_mount_options:1;
 486         unsigned int max_read;
 487         unsigned int blksize;
 488         const char *subtype;
 489
 490         /* fuse_dev pointer to fill in, should contain NULL on entry */
 491         void **fudptr;
 492 };
 493
 494 /**
 495  * A Fuse connection.
 496  *
 497  * This structure is created, when the filesystem is mounted, and is
 498  * destroyed, when the client device is closed and the filesystem is
 499  * unmounted.
 500  */
 501 struct fuse_conn {
 502         /** Lock protecting accessess to  members of this structure */
 503         spinlock_t lock;
 504
 505         /** Refcount */
 506         refcount_t count;
 507
 508         /** Number of fuse_dev's */
 509         atomic_t dev_count;
 510
 511         struct rcu_head rcu;
 512
 513         /** The user id for this mount */
 514         kuid_t user_id;
 515
 516         /** The group id for this mount */
 517         kgid_t group_id;
 518
 519         /** The pid namespace for this mount */
 520         struct pid_namespace *pid_ns;
 521
 522         /** The user namespace for this mount */
 523         struct user_namespace *user_ns;
 524
 525         /** Maximum read size */
 526         unsigned max_read;
 527
 528         /** Maximum write size */
 529         unsigned max_write;
 530
 531         /** Maxmum number of pages that can be used in a single request */
 532         unsigned int max_pages;
 533
 534         /** Input queue */
 535         struct fuse_iqueue iq;
 536
 537         /** The next unique kernel file handle */
 538         atomic64_t khctr;
 539
 540         /** rbtree of fuse_files waiting for poll events indexed by ph */
 541         struct rb_root polled_files;
 542
 543         /** Maximum number of outstanding background requests */
 544         unsigned max_background;
 545
 546         /** Number of background requests at which congestion starts */
 547         unsigned congestion_threshold;
 548
 549         /** Number of requests currently in the background */
 550         unsigned num_background;
 551
 552         /** Number of background requests currently queued for userspace */
 553         unsigned active_background;
 554
 555         /** The list of background requests set aside for later queuing */
 556         struct list_head bg_queue;
 557
 558         /** Protects: max_background, congestion_threshold, num_background,
 559          * active_background, bg_queue, blocked */
 560         spinlock_t bg_lock;
 561
 562         /** Flag indicating that INIT reply has been received. Allocating
 563          * any fuse request will be suspended until the flag is set */
 564         int initialized;
 565
 566         /** Flag indicating if connection is blocked.  This will be
 567             the case before the INIT reply is received, and if there
 568             are too many outstading backgrounds requests */
 569         int blocked;
 570
 571         /** waitq for blocked connection */
 572         wait_queue_head_t blocked_waitq;
 573
 574         /** Connection established, cleared on umount, connection
 575             abort and device release */
 576         unsigned connected;
 577
 578         /** Connection aborted via sysfs */
 579         bool aborted;
 580
 581         /** Connection failed (version mismatch).  Cannot race with
 582             setting other bitfields since it is only set once in INIT
 583             reply, before any other request, and never cleared */
 584         unsigned conn_error:1;
 585
 586         /** Connection successful.  Only set in INIT */
 587         unsigned conn_init:1;
 588
 589         /** Do readpages asynchronously?  Only set in INIT */
 590         unsigned async_read:1;
 591
 592         /** Return an unique read error after abort.  Only set in INIT */
 593         unsigned abort_err:1;
 594
 595         /** Do not send separate SETATTR request before open(O_TRUNC)  */
 596         unsigned atomic_o_trunc:1;
 597
 598         /** Filesystem supports NFS exporting.  Only set in INIT */
 599         unsigned export_support:1;
 600
 601         /** write-back cache policy (default is write-through) */
 602         unsigned writeback_cache:1;
 603
 604         /** allow parallel lookups and readdir (default is serialized) */
 605         unsigned parallel_dirops:1;
 606
 607         /** handle fs handles killing suid/sgid/cap on write/chown/trunc */
 608         unsigned handle_killpriv:1;
 609
 610         /** cache READLINK responses in page cache */
 611         unsigned cache_symlinks:1;
 612
 613         /*
 614          * The following bitfields are only for optimization purposes
 615          * and hence races in setting them will not cause malfunction
 616          */
 617
 618         /** Is open/release not implemented by fs? */
 619         unsigned no_open:1;
 620
 621         /** Is opendir/releasedir not implemented by fs? */
 622         unsigned no_opendir:1;
 623
 624         /** Is fsync not implemented by fs? */
 625         unsigned no_fsync:1;
 626
 627         /** Is fsyncdir not implemented by fs? */
 628         unsigned no_fsyncdir:1;
 629
 630         /** Is flush not implemented by fs? */
 631         unsigned no_flush:1;
 632
 633         /** Is setxattr not implemented by fs? */
 634         unsigned no_setxattr:1;
 635
 636         /** Is getxattr not implemented by fs? */
 637         unsigned no_getxattr:1;
 638
 639         /** Is listxattr not implemented by fs? */
 640         unsigned no_listxattr:1;
 641
 642         /** Is removexattr not implemented by fs? */
 643         unsigned no_removexattr:1;
 644
 645         /** Are posix file locking primitives not implemented by fs? */
 646         unsigned no_lock:1;
 647
 648         /** Is access not implemented by fs? */
 649         unsigned no_access:1;
 650
 651         /** Is create not implemented by fs? */
 652         unsigned no_create:1;
 653
 654         /** Is interrupt not implemented by fs? */
 655         unsigned no_interrupt:1;
 656
 657         /** Is bmap not implemented by fs? */
 658         unsigned no_bmap:1;
 659
 660         /** Is poll not implemented by fs? */
 661         unsigned no_poll:1;
 662
 663         /** Do multi-page cached writes */
 664         unsigned big_writes:1;
 665
 666         /** Don't apply umask to creation modes */
 667         unsigned dont_mask:1;
 668
 669         /** Are BSD file locking primitives not implemented by fs? */
 670         unsigned no_flock:1;
 671
 672         /** Is fallocate not implemented by fs? */
 673         unsigned no_fallocate:1;
 674
 675         /** Is rename with flags implemented by fs? */
 676         unsigned no_rename2:1;
 677
 678         /** Use enhanced/automatic page cache invalidation. */
 679         unsigned auto_inval_data:1;
 680
 681         /** Filesystem is fully reponsible for page cache invalidation. */
 682         unsigned explicit_inval_data:1;
 683
 684         /** Does the filesystem support readdirplus? */
 685         unsigned do_readdirplus:1;
 686
 687         /** Does the filesystem want adaptive readdirplus? */
 688         unsigned readdirplus_auto:1;
 689
 690         /** Does the filesystem support asynchronous direct-IO submission? */
 691         unsigned async_dio:1;
 692
 693         /** Is lseek not implemented by fs? */
 694         unsigned no_lseek:1;
 695
 696         /** Does the filesystem support posix acls? */
 697         unsigned posix_acl:1;
 698
 699         /** Check permissions based on the file mode or not? */
 700         unsigned default_permissions:1;
 701
 702         /** Allow other than the mounter user to access the filesystem ? */
 703         unsigned allow_other:1;
 704
 705         /** Does the filesystem support copy_file_range? */
 706         unsigned no_copy_file_range:1;
 707
 708         /* Send DESTROY request */
 709         unsigned int destroy:1;
 710
 711         /* Delete dentries that have gone stale */
 712         unsigned int delete_stale:1;
 713
 714         /** Do not create entry in fusectl fs */
 715         unsigned int no_control:1;
 716
 717         /** Do not allow MNT_FORCE umount */
 718         unsigned int no_force_umount:1;
 719
 720         /* Do not show mount options */
 721         unsigned int no_mount_options:1;
 722
 723         /** The number of requests waiting for completion */
 724         atomic_t num_waiting;
 725
 726         /** Negotiated minor version */
 727         unsigned minor;
 728
 729         /** Entry on the fuse_conn_list */
 730         struct list_head entry;
 731
 732         /** Device ID from super block */
 733         dev_t dev;
 734
 735         /** Dentries in the control filesystem */
 736         struct dentry *ctl_dentry[FUSE_CTL_NUM_DENTRIES];
 737
 738         /** number of dentries used in the above array */
 739         int ctl_ndents;
 740
 741         /** Key for lock owner ID scrambling */
 742         u32 scramble_key[4];
 743
 744         /** Version counter for attribute changes */
 745         atomic64_t attr_version;
 746
 747         /** Called on final put */
 748         void (*release)(struct fuse_conn *);
 749
 750         /** Super block for this connection. */
 751         struct super_block *sb;
 752
 753         /** Read/write semaphore to hold when accessing sb. */
 754         struct rw_semaphore killsb;
 755
 756         /** List of device instances belonging to this connection */
 757         struct list_head devices;
 758 };
 759
 760 static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
 761 {
 762         return sb->s_fs_info;
 763 }
 764
 765 static inline struct fuse_conn *get_fuse_conn(struct inode *inode)
 766 {
 767         return get_fuse_conn_super(inode->i_sb);
 768 }
 769
 770 static inline struct fuse_inode *get_fuse_inode(struct inode *inode)
 771 {
 772         return container_of(inode, struct fuse_inode, inode);
 773 }
 774
 775 static inline u64 get_node_id(struct inode *inode)
 776 {
 777         return get_fuse_inode(inode)->nodeid;
 778 }
 779
 780 static inline int invalid_nodeid(u64 nodeid)
 781 {
 782         return !nodeid || nodeid == FUSE_ROOT_ID;
 783 }
 784
 785 static inline u64 fuse_get_attr_version(struct fuse_conn *fc)
 786 {
 787         return atomic64_read(&fc->attr_version);
 788 }
 789
 790 /** Device operations */
 791 extern const struct file_operations fuse_dev_operations;
 792
 793 extern const struct dentry_operations fuse_dentry_operations;
 794 extern const struct dentry_operations fuse_root_dentry_operations;
 795
 796 /**
 797  * Inode to nodeid comparison.
 798  */
 799 int fuse_inode_eq(struct inode *inode, void *_nodeidp);
 800
 801 /**
 802  * Get a filled in inode
 803  */
 804 struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
 805                         int generation, struct fuse_attr *attr,
 806                         u64 attr_valid, u64 attr_version);
 807
 808 int fuse_lookup_name(struct super_block *sb, u64 nodeid, const struct qstr *name,
 809                      struct fuse_entry_out *outarg, struct inode **inode);
 810
 811 /**
 812  * Send FORGET command
 813  */
 814 void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget,
 815                        u64 nodeid, u64 nlookup);
 816
 817 struct fuse_forget_link *fuse_alloc_forget(void);
 818
 819 struct fuse_forget_link *fuse_dequeue_forget(struct fuse_iqueue *fiq,
 820                                              unsigned int max,
 821                                              unsigned int *countp);
 822
 823 /*
 824  * Initialize READ or READDIR request
 825  */
 826 struct fuse_io_args {
 827         union {
 828                 struct {
 829                         struct fuse_read_in in;
 830                         u64 attr_ver;
 831                 } read;
 832                 struct {
 833                         struct fuse_write_in in;
 834                         struct fuse_write_out out;
 835                 } write;
 836         };
 837         struct fuse_args_pages ap;
 838         struct fuse_io_priv *io;
 839         struct fuse_file *ff;
 840 };
 841
 842 void fuse_read_args_fill(struct fuse_io_args *ia, struct file *file, loff_t pos,
 843                          size_t count, int opcode);
 844
 845
 846 /**
 847  * Send OPEN or OPENDIR request
 848  */
 849 int fuse_open_common(struct inode *inode, struct file *file, bool isdir);
 850
 851 struct fuse_file *fuse_file_alloc(struct fuse_conn *fc);
 852 void fuse_file_free(struct fuse_file *ff);
 853 void fuse_finish_open(struct inode *inode, struct file *file);
 854
 855 void fuse_sync_release(struct fuse_inode *fi, struct fuse_file *ff, int flags);
 856
 857 /**
 858  * Send RELEASE or RELEASEDIR request
 859  */
 860 void fuse_release_common(struct file *file, bool isdir);
 861
 862 /**
 863  * Send FSYNC or FSYNCDIR request
 864  */
 865 int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
 866                       int datasync, int opcode);
 867
 868 /**
 869  * Notify poll wakeup
 870  */
 871 int fuse_notify_poll_wakeup(struct fuse_conn *fc,
 872                             struct fuse_notify_poll_wakeup_out *outarg);
 873
 874 /**
 875  * Initialize file operations on a regular file
 876  */
 877 void fuse_init_file_inode(struct inode *inode);
 878
 879 /**
 880  * Initialize inode operations on regular files and special files
 881  */
 882 void fuse_init_common(struct inode *inode);
 883
 884 /**
 885  * Initialize inode and file operations on a directory
 886  */
 887 void fuse_init_dir(struct inode *inode);
 888
 889 /**
 890  * Initialize inode operations on a symlink
 891  */
 892 void fuse_init_symlink(struct inode *inode);
 893
 894 /**
 895  * Change attributes of an inode
 896  */
 897 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
 898                             u64 attr_valid, u64 attr_version);
 899
 900 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
 901                                    u64 attr_valid);
 902
 903 /**
 904  * Initialize the client device
 905  */
 906 int fuse_dev_init(void);
 907
 908 /**
 909  * Cleanup the client device
 910  */
 911 void fuse_dev_cleanup(void);
 912
 913 int fuse_ctl_init(void);
 914 void __exit fuse_ctl_cleanup(void);
 915
 916 /**
 917  * Simple request sending that does request allocation and freeing
 918  */
 919 ssize_t fuse_simple_request(struct fuse_conn *fc, struct fuse_args *args);
 920 int fuse_simple_background(struct fuse_conn *fc, struct fuse_args *args,
 921                            gfp_t gfp_flags);
 922
 923 /**
 924  * End a finished request
 925  */
 926 void fuse_request_end(struct fuse_conn *fc, struct fuse_req *req);
 927
 928 /* Abort all requests */
 929 void fuse_abort_conn(struct fuse_conn *fc);
 930 void fuse_wait_aborted(struct fuse_conn *fc);
 931
 932 /**
 933  * Invalidate inode attributes
 934  */
 935 void fuse_invalidate_attr(struct inode *inode);
 936
 937 void fuse_invalidate_entry_cache(struct dentry *entry);
 938
 939 void fuse_invalidate_atime(struct inode *inode);
 940
 941 u64 entry_attr_timeout(struct fuse_entry_out *o);
 942 void fuse_change_entry_timeout(struct dentry *entry, struct fuse_entry_out *o);
 943
 944 /**
 945  * Acquire reference to fuse_conn
 946  */
 947 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc);
 948
 949 /**
 950  * Initialize fuse_conn
 951  */
 952 void fuse_conn_init(struct fuse_conn *fc, struct user_namespace *user_ns,
 953                     const struct fuse_iqueue_ops *fiq_ops, void *fiq_priv);
 954
 955 /**
 956  * Release reference to fuse_conn
 957  */
 958 void fuse_conn_put(struct fuse_conn *fc);
 959
 960 struct fuse_dev *fuse_dev_alloc_install(struct fuse_conn *fc);
 961 struct fuse_dev *fuse_dev_alloc(void);
 962 void fuse_dev_install(struct fuse_dev *fud, struct fuse_conn *fc);
 963 void fuse_dev_free(struct fuse_dev *fud);
 964 void fuse_send_init(struct fuse_conn *fc);
 965
 966 /**
 967  * Fill in superblock and initialize fuse connection
 968  * @sb: partially-initialized superblock to fill in
 969  * @ctx: mount context
 970  */
 971 int fuse_fill_super_common(struct super_block *sb, struct fuse_fs_context *ctx);
 972
 973 /**
 974  * Disassociate fuse connection from superblock and kill the superblock
 975  *
 976  * Calls kill_anon_super(), do not use with bdev mounts.
 977  */
 978 void fuse_kill_sb_anon(struct super_block *sb);
 979
 980 /**
 981  * Add connection to control filesystem
 982  */
 983 int fuse_ctl_add_conn(struct fuse_conn *fc);
 984
 985 /**
 986  * Remove connection from control filesystem
 987  */
 988 void fuse_ctl_remove_conn(struct fuse_conn *fc);
 989
 990 /**
 991  * Is file type valid?
 992  */
 993 int fuse_valid_type(int m);
 994
 995 bool fuse_invalid_attr(struct fuse_attr *attr);
 996
 997 /**
 998  * Is current process allowed to perform filesystem operation?
 999  */
1000 int fuse_allow_current_process(struct fuse_conn *fc);
1001
1002 u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id);
1003
1004 void fuse_update_ctime(struct inode *inode);
1005
1006 int fuse_update_attributes(struct inode *inode, struct file *file);
1007
1008 void fuse_flush_writepages(struct inode *inode);
1009
1010 void fuse_set_nowrite(struct inode *inode);
1011 void fuse_release_nowrite(struct inode *inode);
1012
1013 /**
1014  * File-system tells the kernel to invalidate cache for the given node id.
1015  */
1016 int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
1017                              loff_t offset, loff_t len);
1018
1019 /**
1020  * File-system tells the kernel to invalidate parent attributes and
1021  * the dentry matching parent/name.
1022  *
1023  * If the child_nodeid is non-zero and:
1024  *    - matches the inode number for the dentry matching parent/name,
1025  *    - is not a mount point
1026  *    - is a file or oan empty directory
1027  * then the dentry is unhashed (d_delete()).
1028  */
1029 int fuse_reverse_inval_entry(struct super_block *sb, u64 parent_nodeid,
1030                              u64 child_nodeid, struct qstr *name);
1031
1032 int fuse_do_open(struct fuse_conn *fc, u64 nodeid, struct file *file,
1033                  bool isdir);
1034
1035 /**
1036  * fuse_direct_io() flags
1037  */
1038
1039 /** If set, it is WRITE; otherwise - READ */
1040 #define FUSE_DIO_WRITE (1 << 0)
1041
1042 /** CUSE pass fuse_direct_io() a file which f_mapping->host is not from FUSE */
1043 #define FUSE_DIO_CUSE  (1 << 1)
1044
1045 ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter,
1046                        loff_t *ppos, int flags);
1047 long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
1048                    unsigned int flags);
1049 long fuse_ioctl_common(struct file *file, unsigned int cmd,
1050                        unsigned long arg, unsigned int flags);
1051 __poll_t fuse_file_poll(struct file *file, poll_table *wait);
1052 int fuse_dev_release(struct inode *inode, struct file *file);
1053
1054 bool fuse_write_update_size(struct inode *inode, loff_t pos);
1055
1056 int fuse_flush_times(struct inode *inode, struct fuse_file *ff);
1057 int fuse_write_inode(struct inode *inode, struct writeback_control *wbc);
1058
1059 int fuse_do_setattr(struct dentry *dentry, struct iattr *attr,
1060                     struct file *file);
1061
1062 void fuse_set_initialized(struct fuse_conn *fc);
1063
1064 void fuse_unlock_inode(struct inode *inode, bool locked);
1065 bool fuse_lock_inode(struct inode *inode);
1066
1067 int fuse_setxattr(struct inode *inode, const char *name, const void *value,
1068                   size_t size, int flags);
1069 ssize_t fuse_getxattr(struct inode *inode, const char *name, void *value,
1070                       size_t size);
1071 ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size);
1072 int fuse_removexattr(struct inode *inode, const char *name);
1073 extern const struct xattr_handler *fuse_xattr_handlers[];
1074 extern const struct xattr_handler *fuse_acl_xattr_handlers[];
1075 extern const struct xattr_handler *fuse_no_acl_xattr_handlers[];
1076
1077 struct posix_acl;
1078 struct posix_acl *fuse_get_acl(struct inode *inode, int type);
1079 int fuse_set_acl(struct inode *inode, struct posix_acl *acl, int type);
1080
1081
1082 /* readdir.c */
1083 int fuse_readdir(struct file *file, struct dir_context *ctx);
1084
1085 /**
1086  * Return the number of bytes in an arguments list
1087  */
1088 unsigned int fuse_len_args(unsigned int numargs, struct fuse_arg *args);
1089
1090 /**
1091  * Get the next unique ID for a request
1092  */
1093 u64 fuse_get_unique(struct fuse_iqueue *fiq);
1094 void fuse_free_conn(struct fuse_conn *fc);
1095
1096 #endif /* _FS_FUSE_I_H */