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/** Bias for fi->writectr, meaning new writepages must not be sent */
  39#define FUSE_NOWRITE INT_MIN
  40
  41/** Maximum length of a filename, not including terminating null */
  42
  43/* maximum, small enough for FUSE_MIN_READ_BUFFER*/
  44#define FUSE_NAME_LOW_MAX 1024
  45/* maximum, but needs a request buffer > FUSE_MIN_READ_BUFFER */
  46#define FUSE_NAME_MAX (PATH_MAX - 1)
  47
  48/** Number of dentries for each connection in the control filesystem */
  49#define FUSE_CTL_NUM_DENTRIES 5
  50
  51/* Frequency (in seconds) of request timeout checks, if opted into */
  52#define FUSE_TIMEOUT_TIMER_FREQ 15
  53
  54/** Frequency (in jiffies) of request timeout checks, if opted into */
  55extern const unsigned long fuse_timeout_timer_freq;
  56
  57/*
  58 * Dentries invalidation workqueue period, in seconds.  The value of this
  59 * parameter shall be >= FUSE_DENTRY_INVAL_FREQ_MIN seconds, or 0 (zero), in
  60 * which case no workqueue will be created.
  61 */
  62extern unsigned inval_wq __read_mostly;
  63
  64/** Maximum of max_pages received in init_out */
  65extern unsigned int fuse_max_pages_limit;
  66/*
  67 * Default timeout (in seconds) for the server to reply to a request
  68 * before the connection is aborted, if no timeout was specified on mount.
  69 */
  70extern unsigned int fuse_default_req_timeout;
  71/*
  72 * Max timeout (in seconds) for the server to reply to a request before
  73 * the connection is aborted.
  74 */
  75extern unsigned int fuse_max_req_timeout;
  76
  77/** List of active connections */
  78extern struct list_head fuse_conn_list;
  79
  80/** Global mutex protecting fuse_conn_list and the control filesystem */
  81extern struct mutex fuse_mutex;
  82
  83/** Module parameters */
  84extern unsigned int max_user_bgreq;
  85extern unsigned int max_user_congthresh;
  86
  87/* One forget request */
  88struct fuse_forget_link {
  89	struct fuse_forget_one forget_one;
  90	struct fuse_forget_link *next;
  91};
  92
  93/* Submount lookup tracking */
  94struct fuse_submount_lookup {
  95	/** Refcount */
  96	refcount_t count;
  97
  98	/** Unique ID, which identifies the inode between userspace
  99	 * and kernel */
 100	u64 nodeid;
 101
 102	/** The request used for sending the FORGET message */
 103	struct fuse_forget_link *forget;
 104};
 105
 106/** Container for data related to mapping to backing file */
 107struct fuse_backing {
 108	struct file *file;
 109	struct cred *cred;
 110
 111	/** refcount */
 112	refcount_t count;
 113	struct rcu_head rcu;
 114};
 115
 116/** FUSE inode */
 117struct fuse_inode {
 118	/** Inode data */
 119	struct inode inode;
 120
 121	/** Unique ID, which identifies the inode between userspace
 122	 * and kernel */
 123	u64 nodeid;
 124
 125	/** Number of lookups on this inode */
 126	u64 nlookup;
 127
 128	/** The request used for sending the FORGET message */
 129	struct fuse_forget_link *forget;
 130
 131	/** Time in jiffies until the file attributes are valid */
 132	u64 i_time;
 133
 134	/* Which attributes are invalid */
 135	u32 inval_mask;
 136
 137	/** The sticky bit in inode->i_mode may have been removed, so
 138	    preserve the original mode */
 139	umode_t orig_i_mode;
 140
 141	/* Cache birthtime */
 142	struct timespec64 i_btime;
 143
 144	/** 64 bit inode number */
 145	u64 orig_ino;
 146
 147	/** Version of last attribute change */
 148	u64 attr_version;
 149
 150	union {
 151		/* read/write io cache (regular file only) */
 152		struct {
 153			/* Files usable in writepage.  Protected by fi->lock */
 154			struct list_head write_files;
 155
 156			/* Writepages pending on truncate or fsync */
 157			struct list_head queued_writes;
 158
 159			/* Number of sent writes, a negative bias
 160			 * (FUSE_NOWRITE) means more writes are blocked */
 161			int writectr;
 162
 163			/** Number of files/maps using page cache */
 164			int iocachectr;
 165
 166			/* Waitq for writepage completion */
 167			wait_queue_head_t page_waitq;
 168
 169			/* waitq for direct-io completion */
 170			wait_queue_head_t direct_io_waitq;
 171		};
 172
 173		/* readdir cache (directory only) */
 174		struct {
 175			/* true if fully cached */
 176			bool cached;
 177
 178			/* size of cache */
 179			loff_t size;
 180
 181			/* position at end of cache (position of next entry) */
 182			loff_t pos;
 183
 184			/* version of the cache */
 185			u64 version;
 186
 187			/* modification time of directory when cache was
 188			 * started */
 189			struct timespec64 mtime;
 190
 191			/* iversion of directory when cache was started */
 192			u64 iversion;
 193
 194			/* protects above fields */
 195			spinlock_t lock;
 196		} rdc;
 197	};
 198
 199	/** Miscellaneous bits describing inode state */
 200	unsigned long state;
 201
 202	/** Lock for serializing lookup and readdir for back compatibility*/
 203	struct mutex mutex;
 204
 205	/** Lock to protect write related fields */
 206	spinlock_t lock;
 207
 208#ifdef CONFIG_FUSE_DAX
 209	/*
 210	 * Dax specific inode data
 211	 */
 212	struct fuse_inode_dax *dax;
 213#endif
 214	/** Submount specific lookup tracking */
 215	struct fuse_submount_lookup *submount_lookup;
 216#ifdef CONFIG_FUSE_PASSTHROUGH
 217	/** Reference to backing file in passthrough mode */
 218	struct fuse_backing *fb;
 219#endif
 220
 221	/*
 222	 * The underlying inode->i_blkbits value will not be modified,
 223	 * so preserve the blocksize specified by the server.
 224	 */
 225	u8 cached_i_blkbits;
 226};
 227
 228/** FUSE inode state bits */
 229enum {
 230	/** Advise readdirplus  */
 231	FUSE_I_ADVISE_RDPLUS,
 232	/** Initialized with readdirplus */
 233	FUSE_I_INIT_RDPLUS,
 234	/** An operation changing file size is in progress  */
 235	FUSE_I_SIZE_UNSTABLE,
 236	/* Bad inode */
 237	FUSE_I_BAD,
 238	/* Has btime */
 239	FUSE_I_BTIME,
 240	/* Wants or already has page cache IO */
 241	FUSE_I_CACHE_IO_MODE,
 242	/*
 243	 * Client has exclusive access to the inode, either because fs is local
 244	 * or the fuse server has an exclusive "lease" on distributed fs
 245	 */
 246	FUSE_I_EXCLUSIVE,
 247};
 248
 249struct fuse_conn;
 250struct fuse_mount;
 251union fuse_file_args;
 252
 253/** FUSE specific file data */
 254struct fuse_file {
 255	/** Fuse connection for this file */
 256	struct fuse_mount *fm;
 257
 258	/* Argument space reserved for open/release */
 259	union fuse_file_args *args;
 260
 261	/** Kernel file handle guaranteed to be unique */
 262	u64 kh;
 263
 264	/** File handle used by userspace */
 265	u64 fh;
 266
 267	/** Node id of this file */
 268	u64 nodeid;
 269
 270	/** Refcount */
 271	refcount_t count;
 272
 273	/** FOPEN_* flags returned by open */
 274	u32 open_flags;
 275
 276	/** Entry on inode's write_files list */
 277	struct list_head write_entry;
 278
 279	/* Readdir related */
 280	struct {
 281		/* Dir stream position */
 282		loff_t pos;
 283
 284		/* Offset in cache */
 285		loff_t cache_off;
 286
 287		/* Version of cache we are reading */
 288		u64 version;
 289
 290	} readdir;
 291
 292	/** RB node to be linked on fuse_conn->polled_files */
 293	struct rb_node polled_node;
 294
 295	/** Wait queue head for poll */
 296	wait_queue_head_t poll_wait;
 297
 298	/** Does file hold a fi->iocachectr refcount? */
 299	enum { IOM_NONE, IOM_CACHED, IOM_UNCACHED } iomode;
 300
 301#ifdef CONFIG_FUSE_PASSTHROUGH
 302	/** Reference to backing file in passthrough mode */
 303	struct file *passthrough;
 304	const struct cred *cred;
 305#endif
 306
 307	/** Has flock been performed on this file? */
 308	bool flock:1;
 309};
 310
 311/** One input argument of a request */
 312struct fuse_in_arg {
 313	unsigned size;
 314	const void *value;
 315};
 316
 317/** One output argument of a request */
 318struct fuse_arg {
 319	unsigned size;
 320	void *value;
 321};
 322
 323/** FUSE folio descriptor */
 324struct fuse_folio_desc {
 325	unsigned int length;
 326	unsigned int offset;
 327};
 328
 329struct fuse_args {
 330	uint64_t nodeid;
 331	uint32_t opcode;
 332	uint8_t in_numargs;
 333	uint8_t out_numargs;
 334	uint8_t ext_idx;
 335	bool force:1;
 336	bool noreply:1;
 337	bool nocreds:1;
 338	bool in_pages:1;
 339	bool out_pages:1;
 340	bool user_pages:1;
 341	bool out_argvar:1;
 342	bool page_zeroing:1;
 343	bool page_replace:1;
 344	bool may_block:1;
 345	bool is_ext:1;
 346	bool is_pinned:1;
 347	bool invalidate_vmap:1;
 348	struct fuse_in_arg in_args[4];
 349	struct fuse_arg out_args[2];
 350	void (*end)(struct fuse_mount *fm, struct fuse_args *args, int error);
 351	/* Used for kvec iter backed by vmalloc address */
 352	void *vmap_base;
 353};
 354
 355struct fuse_args_pages {
 356	struct fuse_args args;
 357	struct folio **folios;
 358	struct fuse_folio_desc *descs;
 359	unsigned int num_folios;
 360};
 361
 362struct fuse_release_args {
 363	struct fuse_args args;
 364	struct fuse_release_in inarg;
 365	struct inode *inode;
 366};
 367
 368union fuse_file_args {
 369	/* Used during open() */
 370	struct fuse_open_out open_outarg;
 371	/* Used during release() */
 372	struct fuse_release_args release_args;
 373};
 374
 375#define FUSE_ARGS(args) struct fuse_args args = {}
 376
 377/** The request IO state (for asynchronous processing) */
 378struct fuse_io_priv {
 379	struct kref refcnt;
 380	int async;
 381	spinlock_t lock;
 382	unsigned reqs;
 383	ssize_t bytes;
 384	size_t size;
 385	__u64 offset;
 386	bool write;
 387	bool should_dirty;
 388	int err;
 389	struct kiocb *iocb;
 390	struct completion *done;
 391	bool blocking;
 392};
 393
 394#define FUSE_IO_PRIV_SYNC(i) \
 395{					\
 396	.refcnt = KREF_INIT(1),		\
 397	.async = 0,			\
 398	.iocb = i,			\
 399}
 400
 401/**
 402 * Request flags
 403 *
 404 * FR_ISREPLY:		set if the request has reply
 405 * FR_FORCE:		force sending of the request even if interrupted
 406 * FR_BACKGROUND:	request is sent in the background
 407 * FR_WAITING:		request is counted as "waiting"
 408 * FR_ABORTED:		the request was aborted
 409 * FR_INTERRUPTED:	the request has been interrupted
 410 * FR_LOCKED:		data is being copied to/from the request
 411 * FR_PENDING:		request is not yet in userspace
 412 * FR_SENT:		request is in userspace, waiting for an answer
 413 * FR_FINISHED:		request is finished
 414 * FR_PRIVATE:		request is on private list
 415 * FR_ASYNC:		request is asynchronous
 416 * FR_URING:		request is handled through fuse-io-uring
 417 */
 418enum fuse_req_flag {
 419	FR_ISREPLY,
 420	FR_FORCE,
 421	FR_BACKGROUND,
 422	FR_WAITING,
 423	FR_ABORTED,
 424	FR_INTERRUPTED,
 425	FR_LOCKED,
 426	FR_PENDING,
 427	FR_SENT,
 428	FR_FINISHED,
 429	FR_PRIVATE,
 430	FR_ASYNC,
 431	FR_URING,
 432};
 433
 434/**
 435 * A request to the client
 436 *
 437 * .waitq.lock protects the following fields:
 438 *   - FR_ABORTED
 439 *   - FR_LOCKED (may also be modified under fc->lock, tested under both)
 440 */
 441struct fuse_req {
 442	/** This can be on either pending processing or io lists in
 443	    fuse_conn */
 444	struct list_head list;
 445
 446	/** Entry on the interrupts list  */
 447	struct list_head intr_entry;
 448
 449	/* Input/output arguments */
 450	struct fuse_args *args;
 451
 452	/** refcount */
 453	refcount_t count;
 454
 455	/* Request flags, updated with test/set/clear_bit() */
 456	unsigned long flags;
 457
 458	/* The request input header */
 459	struct {
 460		struct fuse_in_header h;
 461	} in;
 462
 463	/* The request output header */
 464	struct {
 465		struct fuse_out_header h;
 466	} out;
 467
 468	/** Used to wake up the task waiting for completion of request*/
 469	wait_queue_head_t waitq;
 470
 471#if IS_ENABLED(CONFIG_VIRTIO_FS)
 472	/** virtio-fs's physically contiguous buffer for in and out args */
 473	void *argbuf;
 474#endif
 475
 476	/** fuse_mount this request belongs to */
 477	struct fuse_mount *fm;
 478
 479#ifdef CONFIG_FUSE_IO_URING
 480	void *ring_entry;
 481	void *ring_queue;
 482#endif
 483	/** When (in jiffies) the request was created */
 484	unsigned long create_time;
 485};
 486
 487struct fuse_iqueue;
 488
 489/**
 490 * Input queue callbacks
 491 *
 492 * Input queue signalling is device-specific.  For example, the /dev/fuse file
 493 * uses fiq->waitq and fasync to wake processes that are waiting on queue
 494 * readiness.  These callbacks allow other device types to respond to input
 495 * queue activity.
 496 */
 497struct fuse_iqueue_ops {
 498	/**
 499	 * Send one forget
 500	 */
 501	void (*send_forget)(struct fuse_iqueue *fiq, struct fuse_forget_link *link);
 502
 503	/**
 504	 * Send interrupt for request
 505	 */
 506	void (*send_interrupt)(struct fuse_iqueue *fiq, struct fuse_req *req);
 507
 508	/**
 509	 * Send one request
 510	 */
 511	void (*send_req)(struct fuse_iqueue *fiq, struct fuse_req *req);
 512
 513	/**
 514	 * Clean up when fuse_iqueue is destroyed
 515	 */
 516	void (*release)(struct fuse_iqueue *fiq);
 517};
 518
 519/** /dev/fuse input queue operations */
 520extern const struct fuse_iqueue_ops fuse_dev_fiq_ops;
 521
 522struct fuse_iqueue {
 523	/** Connection established */
 524	unsigned connected;
 525
 526	/** Lock protecting accesses to members of this structure */
 527	spinlock_t lock;
 528
 529	/** Readers of the connection are waiting on this */
 530	wait_queue_head_t waitq;
 531
 532	/** The next unique request id */
 533	u64 reqctr;
 534
 535	/** The list of pending requests */
 536	struct list_head pending;
 537
 538	/** Pending interrupts */
 539	struct list_head interrupts;
 540
 541	/** Queue of pending forgets */
 542	struct fuse_forget_link forget_list_head;
 543	struct fuse_forget_link *forget_list_tail;
 544
 545	/** Batching of FORGET requests (positive indicates FORGET batch) */
 546	int forget_batch;
 547
 548	/** O_ASYNC requests */
 549	struct fasync_struct *fasync;
 550
 551	/** Device-specific callbacks */
 552	const struct fuse_iqueue_ops *ops;
 553
 554	/** Device-specific state */
 555	void *priv;
 556};
 557
 558#define FUSE_PQ_HASH_BITS 8
 559#define FUSE_PQ_HASH_SIZE (1 << FUSE_PQ_HASH_BITS)
 560
 561struct fuse_pqueue {
 562	/** Connection established */
 563	unsigned connected;
 564
 565	/** Lock protecting accessess to  members of this structure */
 566	spinlock_t lock;
 567
 568	/** Hash table of requests being processed */
 569	struct list_head *processing;
 570
 571	/** The list of requests under I/O */
 572	struct list_head io;
 573};
 574
 575/**
 576 * Fuse device instance
 577 */
 578struct fuse_dev {
 579	/** Fuse connection for this device */
 580	struct fuse_conn *fc;
 581
 582	/** Processing queue */
 583	struct fuse_pqueue pq;
 584
 585	/** list entry on fc->devices */
 586	struct list_head entry;
 587};
 588
 589enum fuse_dax_mode {
 590	FUSE_DAX_INODE_DEFAULT,	/* default */
 591	FUSE_DAX_ALWAYS,	/* "-o dax=always" */
 592	FUSE_DAX_NEVER,		/* "-o dax=never" */
 593	FUSE_DAX_INODE_USER,	/* "-o dax=inode" */
 594};
 595
 596static inline bool fuse_is_inode_dax_mode(enum fuse_dax_mode mode)
 597{
 598	return mode == FUSE_DAX_INODE_DEFAULT || mode == FUSE_DAX_INODE_USER;
 599}
 600
 601struct fuse_fs_context {
 602	int fd;
 603	struct file *file;
 604	unsigned int rootmode;
 605	kuid_t user_id;
 606	kgid_t group_id;
 607	bool is_bdev:1;
 608	bool fd_present:1;
 609	bool rootmode_present:1;
 610	bool user_id_present:1;
 611	bool group_id_present:1;
 612	bool default_permissions:1;
 613	bool allow_other:1;
 614	bool destroy:1;
 615	bool no_control:1;
 616	bool no_force_umount:1;
 617	bool legacy_opts_show:1;
 618	enum fuse_dax_mode dax_mode;
 619	unsigned int max_read;
 620	unsigned int blksize;
 621	const char *subtype;
 622
 623	/* DAX device, may be NULL */
 624	struct dax_device *dax_dev;
 625
 626	/* fuse_dev pointer to fill in, should contain NULL on entry */
 627	void **fudptr;
 628};
 629
 630struct fuse_sync_bucket {
 631	/* count is a possible scalability bottleneck */
 632	atomic_t count;
 633	wait_queue_head_t waitq;
 634	struct rcu_head rcu;
 635};
 636
 637/**
 638 * A Fuse connection.
 639 *
 640 * This structure is created, when the root filesystem is mounted, and
 641 * is destroyed, when the client device is closed and the last
 642 * fuse_mount is destroyed.
 643 */
 644struct fuse_conn {
 645	/** Lock protecting accessess to  members of this structure */
 646	spinlock_t lock;
 647
 648	/** Refcount */
 649	refcount_t count;
 650
 651	/** Number of fuse_dev's */
 652	atomic_t dev_count;
 653
 654	/** Current epoch for up-to-date dentries */
 655	atomic_t epoch;
 656
 657	struct work_struct epoch_work;
 658
 659	struct rcu_head rcu;
 660
 661	/** The user id for this mount */
 662	kuid_t user_id;
 663
 664	/** The group id for this mount */
 665	kgid_t group_id;
 666
 667	/** The pid namespace for this mount */
 668	struct pid_namespace *pid_ns;
 669
 670	/** The user namespace for this mount */
 671	struct user_namespace *user_ns;
 672
 673	/** Maximum read size */
 674	unsigned max_read;
 675
 676	/** Maximum write size */
 677	unsigned max_write;
 678
 679	/** Maximum number of pages that can be used in a single request */
 680	unsigned int max_pages;
 681
 682	/** Constrain ->max_pages to this value during feature negotiation */
 683	unsigned int max_pages_limit;
 684
 685	/** Input queue */
 686	struct fuse_iqueue iq;
 687
 688	/** The next unique kernel file handle */
 689	atomic64_t khctr;
 690
 691	/** rbtree of fuse_files waiting for poll events indexed by ph */
 692	struct rb_root polled_files;
 693
 694	/** Maximum number of outstanding background requests */
 695	unsigned max_background;
 696
 697	/** Number of background requests at which congestion starts */
 698	unsigned congestion_threshold;
 699
 700	/** Number of requests currently in the background */
 701	unsigned num_background;
 702
 703	/** Number of background requests currently queued for userspace */
 704	unsigned active_background;
 705
 706	/** The list of background requests set aside for later queuing */
 707	struct list_head bg_queue;
 708
 709	/** Protects: max_background, congestion_threshold, num_background,
 710	 * active_background, bg_queue, blocked */
 711	spinlock_t bg_lock;
 712
 713	/** Flag indicating that INIT reply has been received. Allocating
 714	 * any fuse request will be suspended until the flag is set */
 715	int initialized;
 716
 717	/** Flag indicating if connection is blocked.  This will be
 718	    the case before the INIT reply is received, and if there
 719	    are too many outstading backgrounds requests */
 720	int blocked;
 721
 722	/** waitq for blocked connection */
 723	wait_queue_head_t blocked_waitq;
 724
 725	/** Connection established, cleared on umount, connection
 726	    abort and device release */
 727	unsigned connected;
 728
 729	/** Connection aborted via sysfs */
 730	bool aborted;
 731
 732	/** Connection failed (version mismatch).  Cannot race with
 733	    setting other bitfields since it is only set once in INIT
 734	    reply, before any other request, and never cleared */
 735	unsigned conn_error:1;
 736
 737	/** Connection successful.  Only set in INIT */
 738	unsigned conn_init:1;
 739
 740	/** Do readahead asynchronously?  Only set in INIT */
 741	unsigned async_read:1;
 742
 743	/** Return an unique read error after abort.  Only set in INIT */
 744	unsigned abort_err:1;
 745
 746	/** Do not send separate SETATTR request before open(O_TRUNC)  */
 747	unsigned atomic_o_trunc:1;
 748
 749	/** Filesystem supports NFS exporting.  Only set in INIT */
 750	unsigned export_support:1;
 751
 752	/** write-back cache policy (default is write-through) */
 753	unsigned writeback_cache:1;
 754
 755	/** allow parallel lookups and readdir (default is serialized) */
 756	unsigned parallel_dirops:1;
 757
 758	/** handle fs handles killing suid/sgid/cap on write/chown/trunc */
 759	unsigned handle_killpriv:1;
 760
 761	/** cache READLINK responses in page cache */
 762	unsigned cache_symlinks:1;
 763
 764	/* show legacy mount options */
 765	unsigned int legacy_opts_show:1;
 766
 767	/*
 768	 * fs kills suid/sgid/cap on write/chown/trunc. suid is killed on
 769	 * write/trunc only if caller did not have CAP_FSETID.  sgid is killed
 770	 * on write/truncate only if caller did not have CAP_FSETID as well as
 771	 * file has group execute permission.
 772	 */
 773	unsigned handle_killpriv_v2:1;
 774
 775	/*
 776	 * The following bitfields are only for optimization purposes
 777	 * and hence races in setting them will not cause malfunction
 778	 */
 779
 780	/** Is open/release not implemented by fs? */
 781	unsigned no_open:1;
 782
 783	/** Is opendir/releasedir not implemented by fs? */
 784	unsigned no_opendir:1;
 785
 786	/** Is fsync not implemented by fs? */
 787	unsigned no_fsync:1;
 788
 789	/** Is fsyncdir not implemented by fs? */
 790	unsigned no_fsyncdir:1;
 791
 792	/** Is flush not implemented by fs? */
 793	unsigned no_flush:1;
 794
 795	/** Is setxattr not implemented by fs? */
 796	unsigned no_setxattr:1;
 797
 798	/** Does file server support extended setxattr */
 799	unsigned setxattr_ext:1;
 800
 801	/** Is getxattr not implemented by fs? */
 802	unsigned no_getxattr:1;
 803
 804	/** Is listxattr not implemented by fs? */
 805	unsigned no_listxattr:1;
 806
 807	/** Is removexattr not implemented by fs? */
 808	unsigned no_removexattr:1;
 809
 810	/** Are posix file locking primitives not implemented by fs? */
 811	unsigned no_lock:1;
 812
 813	/** Is access not implemented by fs? */
 814	unsigned no_access:1;
 815
 816	/** Is create not implemented by fs? */
 817	unsigned no_create:1;
 818
 819	/** Is interrupt not implemented by fs? */
 820	unsigned no_interrupt:1;
 821
 822	/** Is bmap not implemented by fs? */
 823	unsigned no_bmap:1;
 824
 825	/** Is poll not implemented by fs? */
 826	unsigned no_poll:1;
 827
 828	/** Do multi-page cached writes */
 829	unsigned big_writes:1;
 830
 831	/** Don't apply umask to creation modes */
 832	unsigned dont_mask:1;
 833
 834	/** Are BSD file locking primitives not implemented by fs? */
 835	unsigned no_flock:1;
 836
 837	/** Is fallocate not implemented by fs? */
 838	unsigned no_fallocate:1;
 839
 840	/** Is rename with flags implemented by fs? */
 841	unsigned no_rename2:1;
 842
 843	/** Use enhanced/automatic page cache invalidation. */
 844	unsigned auto_inval_data:1;
 845
 846	/** Filesystem is fully responsible for page cache invalidation. */
 847	unsigned explicit_inval_data:1;
 848
 849	/** Does the filesystem support readdirplus? */
 850	unsigned do_readdirplus:1;
 851
 852	/** Does the filesystem want adaptive readdirplus? */
 853	unsigned readdirplus_auto:1;
 854
 855	/** Does the filesystem support asynchronous direct-IO submission? */
 856	unsigned async_dio:1;
 857
 858	/** Is lseek not implemented by fs? */
 859	unsigned no_lseek:1;
 860
 861	/** Does the filesystem support posix acls? */
 862	unsigned posix_acl:1;
 863
 864	/** Check permissions based on the file mode or not? */
 865	unsigned default_permissions:1;
 866
 867	/** Allow other than the mounter user to access the filesystem ? */
 868	unsigned allow_other:1;
 869
 870	/** Does the filesystem support copy_file_range? */
 871	unsigned no_copy_file_range:1;
 872
 873	/** Does the filesystem support copy_file_range_64? */
 874	unsigned no_copy_file_range_64:1;
 875
 876	/* Send DESTROY request */
 877	unsigned int destroy:1;
 878
 879	/* Delete dentries that have gone stale */
 880	unsigned int delete_stale:1;
 881
 882	/** Do not create entry in fusectl fs */
 883	unsigned int no_control:1;
 884
 885	/** Do not allow MNT_FORCE umount */
 886	unsigned int no_force_umount:1;
 887
 888	/* Auto-mount submounts announced by the server */
 889	unsigned int auto_submounts:1;
 890
 891	/* Propagate syncfs() to server */
 892	unsigned int sync_fs:1;
 893
 894	/* Initialize security xattrs when creating a new inode */
 895	unsigned int init_security:1;
 896
 897	/* Add supplementary group info when creating a new inode */
 898	unsigned int create_supp_group:1;
 899
 900	/* Does the filesystem support per inode DAX? */
 901	unsigned int inode_dax:1;
 902
 903	/* Is tmpfile not implemented by fs? */
 904	unsigned int no_tmpfile:1;
 905
 906	/* Relax restrictions to allow shared mmap in FOPEN_DIRECT_IO mode */
 907	unsigned int direct_io_allow_mmap:1;
 908
 909	/* Is statx not implemented by fs? */
 910	unsigned int no_statx:1;
 911
 912	/** Passthrough support for read/write IO */
 913	unsigned int passthrough:1;
 914
 915	/* Use pages instead of pointer for kernel I/O */
 916	unsigned int use_pages_for_kvec_io:1;
 917
 918	/* Is link not implemented by fs? */
 919	unsigned int no_link:1;
 920
 921	/* Is synchronous FUSE_INIT allowed? */
 922	unsigned int sync_init:1;
 923
 924	/* Use io_uring for communication */
 925	unsigned int io_uring;
 926
 927	/** Maximum stack depth for passthrough backing files */
 928	int max_stack_depth;
 929
 930	/** The number of requests waiting for completion */
 931	atomic_t num_waiting;
 932
 933	/** Negotiated minor version */
 934	unsigned minor;
 935
 936	/** Entry on the fuse_conn_list */
 937	struct list_head entry;
 938
 939	/** Device ID from the root super block */
 940	dev_t dev;
 941
 942	/** Key for lock owner ID scrambling */
 943	u32 scramble_key[4];
 944
 945	/** Version counter for attribute changes */
 946	atomic64_t attr_version;
 947
 948	/** Version counter for evict inode */
 949	atomic64_t evict_ctr;
 950
 951	/* maximum file name length */
 952	u32 name_max;
 953
 954	/** Called on final put */
 955	void (*release)(struct fuse_conn *);
 956
 957	/**
 958	 * Read/write semaphore to hold when accessing the sb of any
 959	 * fuse_mount belonging to this connection
 960	 */
 961	struct rw_semaphore killsb;
 962
 963	/** List of device instances belonging to this connection */
 964	struct list_head devices;
 965
 966#ifdef CONFIG_FUSE_DAX
 967	/* Dax mode */
 968	enum fuse_dax_mode dax_mode;
 969
 970	/* Dax specific conn data, non-NULL if DAX is enabled */
 971	struct fuse_conn_dax *dax;
 972#endif
 973
 974	/** List of filesystems using this connection */
 975	struct list_head mounts;
 976
 977	/* New writepages go into this bucket */
 978	struct fuse_sync_bucket __rcu *curr_bucket;
 979
 980#ifdef CONFIG_FUSE_PASSTHROUGH
 981	/** IDR for backing files ids */
 982	struct idr backing_files_map;
 983#endif
 984
 985#ifdef CONFIG_FUSE_IO_URING
 986	/**  uring connection information*/
 987	struct fuse_ring *ring;
 988#endif
 989
 990	/** Only used if the connection opts into request timeouts */
 991	struct {
 992		/* Worker for checking if any requests have timed out */
 993		struct delayed_work work;
 994
 995		/* Request timeout (in jiffies). 0 = no timeout */
 996		unsigned int req_timeout;
 997	} timeout;
 998};
 999
1000/*
1001 * Represents a mounted filesystem, potentially a submount.
1002 *
1003 * This object allows sharing a fuse_conn between separate mounts to
1004 * allow submounts with dedicated superblocks and thus separate device
1005 * IDs.
1006 */
1007struct fuse_mount {
1008	/* Underlying (potentially shared) connection to the FUSE server */
1009	struct fuse_conn *fc;
1010
1011	/*
1012	 * Super block for this connection (fc->killsb must be held when
1013	 * accessing this).
1014	 */
1015	struct super_block *sb;
1016
1017	/* Entry on fc->mounts */
1018	struct list_head fc_entry;
1019	struct rcu_head rcu;
1020};
1021
1022/*
1023 * Empty header for FUSE opcodes without specific header needs.
1024 * Used as a placeholder in args->in_args[0] for consistency
1025 * across all FUSE operations, simplifying request handling.
1026 */
1027struct fuse_zero_header {};
1028
1029static inline void fuse_set_zero_arg0(struct fuse_args *args)
1030{
1031	args->in_args[0].size = sizeof(struct fuse_zero_header);
1032	args->in_args[0].value = NULL;
1033}
1034
1035static inline struct fuse_mount *get_fuse_mount_super(struct super_block *sb)
1036{
1037	return sb->s_fs_info;
1038}
1039
1040static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
1041{
1042	return get_fuse_mount_super(sb)->fc;
1043}
1044
1045static inline struct fuse_mount *get_fuse_mount(struct inode *inode)
1046{
1047	return get_fuse_mount_super(inode->i_sb);
1048}
1049
1050static inline struct fuse_conn *get_fuse_conn(struct inode *inode)
1051{
1052	return get_fuse_mount_super(inode->i_sb)->fc;
1053}
1054
1055static inline struct fuse_inode *get_fuse_inode(const struct inode *inode)
1056{
1057	return container_of(inode, struct fuse_inode, inode);
1058}
1059
1060static inline u64 get_node_id(struct inode *inode)
1061{
1062	return get_fuse_inode(inode)->nodeid;
1063}
1064
1065static inline int invalid_nodeid(u64 nodeid)
1066{
1067	return !nodeid || nodeid == FUSE_ROOT_ID;
1068}
1069
1070static inline u64 fuse_get_attr_version(struct fuse_conn *fc)
1071{
1072	return atomic64_read(&fc->attr_version);
1073}
1074
1075static inline u64 fuse_get_evict_ctr(struct fuse_conn *fc)
1076{
1077	return atomic64_read(&fc->evict_ctr);
1078}
1079
1080static inline bool fuse_stale_inode(const struct inode *inode, int generation,
1081				    struct fuse_attr *attr)
1082{
1083	return inode->i_generation != generation ||
1084		inode_wrong_type(inode, attr->mode);
1085}
1086
1087static inline void fuse_make_bad(struct inode *inode)
1088{
1089	set_bit(FUSE_I_BAD, &get_fuse_inode(inode)->state);
1090}
1091
1092static inline bool fuse_is_bad(struct inode *inode)
1093{
1094	return unlikely(test_bit(FUSE_I_BAD, &get_fuse_inode(inode)->state));
1095}
1096
1097static inline bool fuse_inode_is_exclusive(const struct inode *inode)
1098{
1099	const struct fuse_inode *fi = get_fuse_inode(inode);
1100
1101	return test_bit(FUSE_I_EXCLUSIVE, &fi->state);
1102}
1103
1104static inline struct folio **fuse_folios_alloc(unsigned int nfolios, gfp_t flags,
1105					       struct fuse_folio_desc **desc)
1106{
1107	struct folio **folios;
1108
1109	folios = kzalloc(nfolios * (sizeof(struct folio *) +
1110				    sizeof(struct fuse_folio_desc)), flags);
1111	*desc = (void *) (folios + nfolios);
1112
1113	return folios;
1114}
1115
1116static inline void fuse_folio_descs_length_init(struct fuse_folio_desc *descs,
1117						unsigned int index,
1118						unsigned int nr_folios)
1119{
1120	int i;
1121
1122	for (i = index; i < index + nr_folios; i++)
1123		descs[i].length = PAGE_SIZE - descs[i].offset;
1124}
1125
1126static inline void fuse_sync_bucket_dec(struct fuse_sync_bucket *bucket)
1127{
1128	/* Need RCU protection to prevent use after free after the decrement */
1129	rcu_read_lock();
1130	if (atomic_dec_and_test(&bucket->count))
1131		wake_up(&bucket->waitq);
1132	rcu_read_unlock();
1133}
1134
1135/** Device operations */
1136extern const struct file_operations fuse_dev_operations;
1137
1138extern const struct dentry_operations fuse_dentry_operations;
1139
1140/**
1141 * Get a filled in inode
1142 */
1143struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
1144			int generation, struct fuse_attr *attr,
1145			u64 attr_valid, u64 attr_version,
1146			u64 evict_ctr);
1147
1148int fuse_lookup_name(struct super_block *sb, u64 nodeid, const struct qstr *name,
1149		     struct fuse_entry_out *outarg, struct inode **inode);
1150
1151/**
1152 * Send FORGET command
1153 */
1154void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget,
1155		       u64 nodeid, u64 nlookup);
1156
1157struct fuse_forget_link *fuse_alloc_forget(void);
1158
1159/*
1160 * Initialize READ or READDIR request
1161 */
1162struct fuse_io_args {
1163	union {
1164		struct {
1165			struct fuse_read_in in;
1166			u64 attr_ver;
1167		} read;
1168		struct {
1169			struct fuse_write_in in;
1170			struct fuse_write_out out;
1171			bool folio_locked;
1172		} write;
1173	};
1174	struct fuse_args_pages ap;
1175	struct fuse_io_priv *io;
1176	struct fuse_file *ff;
1177};
1178
1179void fuse_read_args_fill(struct fuse_io_args *ia, struct file *file, loff_t pos,
1180			 size_t count, int opcode);
1181
1182
1183struct fuse_file *fuse_file_alloc(struct fuse_mount *fm, bool release);
1184void fuse_file_free(struct fuse_file *ff);
1185int fuse_finish_open(struct inode *inode, struct file *file);
1186
1187void fuse_sync_release(struct fuse_inode *fi, struct fuse_file *ff,
1188		       unsigned int flags);
1189
1190/**
1191 * Send RELEASE or RELEASEDIR request
1192 */
1193void fuse_release_common(struct file *file, bool isdir);
1194
1195/**
1196 * Send FSYNC or FSYNCDIR request
1197 */
1198int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
1199		      int datasync, int opcode);
1200
1201/**
1202 * Notify poll wakeup
1203 */
1204int fuse_notify_poll_wakeup(struct fuse_conn *fc,
1205			    struct fuse_notify_poll_wakeup_out *outarg);
1206
1207/**
1208 * Initialize file operations on a regular file
1209 */
1210void fuse_init_file_inode(struct inode *inode, unsigned int flags);
1211
1212/**
1213 * Initialize inode operations on regular files and special files
1214 */
1215void fuse_init_common(struct inode *inode);
1216
1217/**
1218 * Initialize inode and file operations on a directory
1219 */
1220void fuse_init_dir(struct inode *inode);
1221
1222/**
1223 * Initialize inode operations on a symlink
1224 */
1225void fuse_init_symlink(struct inode *inode);
1226
1227/**
1228 * Change attributes of an inode
1229 */
1230void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
1231			    struct fuse_statx *sx,
1232			    u64 attr_valid, u64 attr_version);
1233
1234void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
1235				   struct fuse_statx *sx,
1236				   u64 attr_valid, u32 cache_mask,
1237				   u64 evict_ctr);
1238
1239u32 fuse_get_cache_mask(struct inode *inode);
1240
1241/**
1242 * Initialize the client device
1243 */
1244int fuse_dev_init(void);
1245
1246/**
1247 * Cleanup the client device
1248 */
1249void fuse_dev_cleanup(void);
1250
1251int fuse_ctl_init(void);
1252void __exit fuse_ctl_cleanup(void);
1253
1254/**
1255 * Simple request sending that does request allocation and freeing
1256 */
1257ssize_t __fuse_simple_request(struct mnt_idmap *idmap,
1258			      struct fuse_mount *fm,
1259			      struct fuse_args *args);
1260
1261static inline ssize_t fuse_simple_request(struct fuse_mount *fm, struct fuse_args *args)
1262{
1263	return __fuse_simple_request(&invalid_mnt_idmap, fm, args);
1264}
1265
1266static inline ssize_t fuse_simple_idmap_request(struct mnt_idmap *idmap,
1267						struct fuse_mount *fm,
1268						struct fuse_args *args)
1269{
1270	return __fuse_simple_request(idmap, fm, args);
1271}
1272
1273int fuse_simple_background(struct fuse_mount *fm, struct fuse_args *args,
1274			   gfp_t gfp_flags);
1275
1276/**
1277 * Assign a unique id to a fuse request
1278 */
1279void fuse_request_assign_unique(struct fuse_iqueue *fiq, struct fuse_req *req);
1280
1281/**
1282 * End a finished request
1283 */
1284void fuse_request_end(struct fuse_req *req);
1285
1286/* Abort all requests */
1287void fuse_abort_conn(struct fuse_conn *fc);
1288void fuse_wait_aborted(struct fuse_conn *fc);
1289
1290/* Check if any requests timed out */
1291void fuse_check_timeout(struct work_struct *work);
1292
1293void fuse_dentry_tree_init(void);
1294void fuse_dentry_tree_cleanup(void);
1295
1296void fuse_epoch_work(struct work_struct *work);
1297
1298/**
1299 * Invalidate inode attributes
1300 */
1301
1302/* Attributes possibly changed on data modification */
1303#define FUSE_STATX_MODIFY	(STATX_MTIME | STATX_CTIME | STATX_BLOCKS)
1304
1305/* Attributes possibly changed on data and/or size modification */
1306#define FUSE_STATX_MODSIZE	(FUSE_STATX_MODIFY | STATX_SIZE)
1307
1308void fuse_invalidate_attr(struct inode *inode);
1309void fuse_invalidate_attr_mask(struct inode *inode, u32 mask);
1310
1311void fuse_invalidate_entry_cache(struct dentry *entry);
1312
1313void fuse_invalidate_atime(struct inode *inode);
1314
1315u64 fuse_time_to_jiffies(u64 sec, u32 nsec);
1316#define ATTR_TIMEOUT(o) \
1317	fuse_time_to_jiffies((o)->attr_valid, (o)->attr_valid_nsec)
1318
1319void fuse_change_entry_timeout(struct dentry *entry, struct fuse_entry_out *o);
1320
1321/**
1322 * Acquire reference to fuse_conn
1323 */
1324struct fuse_conn *fuse_conn_get(struct fuse_conn *fc);
1325
1326/**
1327 * Initialize the fuse processing queue
1328 */
1329void fuse_pqueue_init(struct fuse_pqueue *fpq);
1330
1331/**
1332 * Initialize fuse_conn
1333 */
1334void fuse_conn_init(struct fuse_conn *fc, struct fuse_mount *fm,
1335		    struct user_namespace *user_ns,
1336		    const struct fuse_iqueue_ops *fiq_ops, void *fiq_priv);
1337
1338/**
1339 * Release reference to fuse_conn
1340 */
1341void fuse_conn_put(struct fuse_conn *fc);
1342
1343struct fuse_dev *fuse_dev_alloc_install(struct fuse_conn *fc);
1344struct fuse_dev *fuse_dev_alloc(void);
1345void fuse_dev_install(struct fuse_dev *fud, struct fuse_conn *fc);
1346void fuse_dev_free(struct fuse_dev *fud);
1347int fuse_send_init(struct fuse_mount *fm);
1348
1349/**
1350 * Fill in superblock and initialize fuse connection
1351 * @sb: partially-initialized superblock to fill in
1352 * @ctx: mount context
1353 */
1354int fuse_fill_super_common(struct super_block *sb, struct fuse_fs_context *ctx);
1355
1356/*
1357 * Remove the mount from the connection
1358 *
1359 * Returns whether this was the last mount
1360 */
1361bool fuse_mount_remove(struct fuse_mount *fm);
1362
1363/*
1364 * Setup context ops for submounts
1365 */
1366int fuse_init_fs_context_submount(struct fs_context *fsc);
1367
1368/*
1369 * Shut down the connection (possibly sending DESTROY request).
1370 */
1371void fuse_conn_destroy(struct fuse_mount *fm);
1372
1373/* Drop the connection and free the fuse mount */
1374void fuse_mount_destroy(struct fuse_mount *fm);
1375
1376/**
1377 * Add connection to control filesystem
1378 */
1379int fuse_ctl_add_conn(struct fuse_conn *fc);
1380
1381/**
1382 * Remove connection from control filesystem
1383 */
1384void fuse_ctl_remove_conn(struct fuse_conn *fc);
1385
1386/**
1387 * Is file type valid?
1388 */
1389int fuse_valid_type(int m);
1390
1391bool fuse_invalid_attr(struct fuse_attr *attr);
1392
1393/**
1394 * Is current process allowed to perform filesystem operation?
1395 */
1396bool fuse_allow_current_process(struct fuse_conn *fc);
1397
1398u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id);
1399
1400void fuse_flush_time_update(struct inode *inode);
1401void fuse_update_ctime(struct inode *inode);
1402
1403int fuse_update_attributes(struct inode *inode, struct file *file, u32 mask);
1404
1405void fuse_flush_writepages(struct inode *inode);
1406
1407void fuse_set_nowrite(struct inode *inode);
1408void fuse_release_nowrite(struct inode *inode);
1409
1410/**
1411 * Scan all fuse_mounts belonging to fc to find the first where
1412 * ilookup5() returns a result.  Return that result and the
1413 * respective fuse_mount in *fm (unless fm is NULL).
1414 *
1415 * The caller must hold fc->killsb.
1416 */
1417struct inode *fuse_ilookup(struct fuse_conn *fc, u64 nodeid,
1418			   struct fuse_mount **fm);
1419
1420/**
1421 * File-system tells the kernel to invalidate cache for the given node id.
1422 */
1423int fuse_reverse_inval_inode(struct fuse_conn *fc, u64 nodeid,
1424			     loff_t offset, loff_t len);
1425
1426/**
1427 * File-system tells the kernel to invalidate parent attributes and
1428 * the dentry matching parent/name.
1429 *
1430 * If the child_nodeid is non-zero and:
1431 *    - matches the inode number for the dentry matching parent/name,
1432 *    - is not a mount point
1433 *    - is a file or oan empty directory
1434 * then the dentry is unhashed (d_delete()).
1435 */
1436int fuse_reverse_inval_entry(struct fuse_conn *fc, u64 parent_nodeid,
1437			     u64 child_nodeid, struct qstr *name, u32 flags);
1438
1439/*
1440 * Try to prune this inode.  If neither the inode itself nor dentries associated
1441 * with this inode have any external reference, then the inode can be freed.
1442 */
1443void fuse_try_prune_one_inode(struct fuse_conn *fc, u64 nodeid);
1444
1445int fuse_do_open(struct fuse_mount *fm, u64 nodeid, struct file *file,
1446		 bool isdir);
1447
1448/**
1449 * fuse_direct_io() flags
1450 */
1451
1452/** If set, it is WRITE; otherwise - READ */
1453#define FUSE_DIO_WRITE (1 << 0)
1454
1455/** CUSE pass fuse_direct_io() a file which f_mapping->host is not from FUSE */
1456#define FUSE_DIO_CUSE  (1 << 1)
1457
1458ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter,
1459		       loff_t *ppos, int flags);
1460long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
1461		   unsigned int flags);
1462long fuse_ioctl_common(struct file *file, unsigned int cmd,
1463		       unsigned long arg, unsigned int flags);
1464__poll_t fuse_file_poll(struct file *file, poll_table *wait);
1465int fuse_dev_release(struct inode *inode, struct file *file);
1466
1467bool fuse_write_update_attr(struct inode *inode, loff_t pos, ssize_t written);
1468
1469int fuse_flush_times(struct inode *inode, struct fuse_file *ff);
1470int fuse_write_inode(struct inode *inode, struct writeback_control *wbc);
1471
1472int fuse_do_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
1473		    struct iattr *attr, struct file *file);
1474
1475void fuse_set_initialized(struct fuse_conn *fc);
1476
1477void fuse_unlock_inode(struct inode *inode, bool locked);
1478bool fuse_lock_inode(struct inode *inode);
1479
1480int fuse_setxattr(struct inode *inode, const char *name, const void *value,
1481		  size_t size, int flags, unsigned int extra_flags);
1482ssize_t fuse_getxattr(struct inode *inode, const char *name, void *value,
1483		      size_t size);
1484ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size);
1485int fuse_removexattr(struct inode *inode, const char *name);
1486extern const struct xattr_handler * const fuse_xattr_handlers[];
1487
1488struct posix_acl;
1489struct posix_acl *fuse_get_inode_acl(struct inode *inode, int type, bool rcu);
1490struct posix_acl *fuse_get_acl(struct mnt_idmap *idmap,
1491			       struct dentry *dentry, int type);
1492int fuse_set_acl(struct mnt_idmap *, struct dentry *dentry,
1493		 struct posix_acl *acl, int type);
1494
1495/* readdir.c */
1496int fuse_readdir(struct file *file, struct dir_context *ctx);
1497
1498/**
1499 * Return the number of bytes in an arguments list
1500 */
1501unsigned int fuse_len_args(unsigned int numargs, struct fuse_arg *args);
1502
1503/**
1504 * Get the next unique ID for a request
1505 */
1506u64 fuse_get_unique(struct fuse_iqueue *fiq);
1507void fuse_free_conn(struct fuse_conn *fc);
1508
1509/* dax.c */
1510
1511#define FUSE_IS_DAX(inode) (IS_ENABLED(CONFIG_FUSE_DAX) && IS_DAX(inode))
1512
1513ssize_t fuse_dax_read_iter(struct kiocb *iocb, struct iov_iter *to);
1514ssize_t fuse_dax_write_iter(struct kiocb *iocb, struct iov_iter *from);
1515int fuse_dax_mmap(struct file *file, struct vm_area_struct *vma);
1516int fuse_dax_break_layouts(struct inode *inode, u64 dmap_start, u64 dmap_end);
1517int fuse_dax_conn_alloc(struct fuse_conn *fc, enum fuse_dax_mode mode,
1518			struct dax_device *dax_dev);
1519void fuse_dax_conn_free(struct fuse_conn *fc);
1520bool fuse_dax_inode_alloc(struct super_block *sb, struct fuse_inode *fi);
1521void fuse_dax_inode_init(struct inode *inode, unsigned int flags);
1522void fuse_dax_inode_cleanup(struct inode *inode);
1523void fuse_dax_dontcache(struct inode *inode, unsigned int flags);
1524bool fuse_dax_check_alignment(struct fuse_conn *fc, unsigned int map_alignment);
1525void fuse_dax_cancel_work(struct fuse_conn *fc);
1526
1527/* ioctl.c */
1528long fuse_file_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
1529long fuse_file_compat_ioctl(struct file *file, unsigned int cmd,
1530			    unsigned long arg);
1531int fuse_fileattr_get(struct dentry *dentry, struct file_kattr *fa);
1532int fuse_fileattr_set(struct mnt_idmap *idmap,
1533		      struct dentry *dentry, struct file_kattr *fa);
1534
1535/* iomode.c */
1536int fuse_file_cached_io_open(struct inode *inode, struct fuse_file *ff);
1537int fuse_inode_uncached_io_start(struct fuse_inode *fi,
1538				 struct fuse_backing *fb);
1539void fuse_inode_uncached_io_end(struct fuse_inode *fi);
1540
1541int fuse_file_io_open(struct file *file, struct inode *inode);
1542void fuse_file_io_release(struct fuse_file *ff, struct inode *inode);
1543
1544/* file.c */
1545struct fuse_file *fuse_file_open(struct fuse_mount *fm, u64 nodeid,
1546				 unsigned int open_flags, bool isdir);
1547void fuse_file_release(struct inode *inode, struct fuse_file *ff,
1548		       unsigned int open_flags, fl_owner_t id, bool isdir);
1549
1550/* backing.c */
1551#ifdef CONFIG_FUSE_PASSTHROUGH
1552struct fuse_backing *fuse_backing_get(struct fuse_backing *fb);
1553void fuse_backing_put(struct fuse_backing *fb);
1554struct fuse_backing *fuse_backing_lookup(struct fuse_conn *fc, int backing_id);
1555#else
1556
1557static inline struct fuse_backing *fuse_backing_get(struct fuse_backing *fb)
1558{
1559	return NULL;
1560}
1561
1562static inline void fuse_backing_put(struct fuse_backing *fb)
1563{
1564}
1565static inline struct fuse_backing *fuse_backing_lookup(struct fuse_conn *fc,
1566						       int backing_id)
1567{
1568	return NULL;
1569}
1570#endif
1571
1572void fuse_backing_files_init(struct fuse_conn *fc);
1573void fuse_backing_files_free(struct fuse_conn *fc);
1574int fuse_backing_open(struct fuse_conn *fc, struct fuse_backing_map *map);
1575int fuse_backing_close(struct fuse_conn *fc, int backing_id);
1576
1577/* passthrough.c */
1578static inline struct fuse_backing *fuse_inode_backing(struct fuse_inode *fi)
1579{
1580#ifdef CONFIG_FUSE_PASSTHROUGH
1581	return READ_ONCE(fi->fb);
1582#else
1583	return NULL;
1584#endif
1585}
1586
1587static inline struct fuse_backing *fuse_inode_backing_set(struct fuse_inode *fi,
1588							  struct fuse_backing *fb)
1589{
1590#ifdef CONFIG_FUSE_PASSTHROUGH
1591	return xchg(&fi->fb, fb);
1592#else
1593	return NULL;
1594#endif
1595}
1596
1597struct fuse_backing *fuse_passthrough_open(struct file *file, int backing_id);
1598void fuse_passthrough_release(struct fuse_file *ff, struct fuse_backing *fb);
1599
1600static inline struct file *fuse_file_passthrough(struct fuse_file *ff)
1601{
1602#ifdef CONFIG_FUSE_PASSTHROUGH
1603	return ff->passthrough;
1604#else
1605	return NULL;
1606#endif
1607}
1608
1609ssize_t fuse_passthrough_read_iter(struct kiocb *iocb, struct iov_iter *iter);
1610ssize_t fuse_passthrough_write_iter(struct kiocb *iocb, struct iov_iter *iter);
1611ssize_t fuse_passthrough_splice_read(struct file *in, loff_t *ppos,
1612				     struct pipe_inode_info *pipe,
1613				     size_t len, unsigned int flags);
1614ssize_t fuse_passthrough_splice_write(struct pipe_inode_info *pipe,
1615				      struct file *out, loff_t *ppos,
1616				      size_t len, unsigned int flags);
1617ssize_t fuse_passthrough_mmap(struct file *file, struct vm_area_struct *vma);
1618
1619#ifdef CONFIG_SYSCTL
1620extern int fuse_sysctl_register(void);
1621extern void fuse_sysctl_unregister(void);
1622#else
1623#define fuse_sysctl_register()		(0)
1624#define fuse_sysctl_unregister()	do { } while (0)
1625#endif /* CONFIG_SYSCTL */
1626
1627#endif /* _FS_FUSE_I_H */