1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 FUSE: Filesystem in Userspace 4 Copyright (C) 2001-2008 Miklos Szeredi <miklos@szeredi.hu> 5 */ 6 7 #ifndef _FS_FUSE_I_H 8 #define _FS_FUSE_I_H 9 10 #ifndef pr_fmt 11 # define pr_fmt(fmt) "fuse: " fmt 12 #endif 13 14 #include "args.h" 15 #include <linux/fuse.h> 16 #include <linux/fs.h> 17 #include <linux/mount.h> 18 #include <linux/wait.h> 19 #include <linux/list.h> 20 #include <linux/spinlock.h> 21 #include <linux/mm.h> 22 #include <linux/backing-dev.h> 23 #include <linux/mutex.h> 24 #include <linux/rwsem.h> 25 #include <linux/rbtree.h> 26 #include <linux/poll.h> 27 #include <linux/workqueue.h> 28 #include <linux/kref.h> 29 #include <linux/xattr.h> 30 #include <linux/pid_namespace.h> 31 #include <linux/refcount.h> 32 #include <linux/user_namespace.h> 33 34 /** Default max number of pages that can be used in a single read request */ 35 #define FUSE_DEFAULT_MAX_PAGES_PER_REQ 32 36 37 /** Bias for fi->writectr, meaning new writepages must not be sent */ 38 #define FUSE_NOWRITE INT_MIN 39 40 /** Maximum length of a filename, not including terminating null */ 41 42 /* maximum, small enough for FUSE_MIN_READ_BUFFER*/ 43 #define FUSE_NAME_LOW_MAX 1024 44 /* maximum, but needs a request buffer > FUSE_MIN_READ_BUFFER */ 45 #define FUSE_NAME_MAX (PATH_MAX - 1) 46 47 /** Number of dentries for each connection in the control filesystem */ 48 #define FUSE_CTL_NUM_DENTRIES 5 49 50 /* 51 * Dentries invalidation workqueue period, in seconds. The value of this 52 * parameter shall be >= FUSE_DENTRY_INVAL_FREQ_MIN seconds, or 0 (zero), in 53 * which case no workqueue will be created. 54 */ 55 extern unsigned inval_wq __read_mostly; 56 57 /** Maximum of max_pages received in init_out */ 58 extern unsigned int fuse_max_pages_limit; 59 60 /** List of active connections */ 61 extern struct list_head fuse_conn_list; 62 63 /** Global mutex protecting fuse_conn_list and the control filesystem */ 64 extern struct mutex fuse_mutex; 65 66 /** Module parameters */ 67 extern unsigned int max_user_bgreq; 68 extern unsigned int max_user_congthresh; 69 70 struct fuse_forget_link; 71 72 /** 73 * struct fuse_submount_lookup - Submount lookup tracking 74 */ 75 struct fuse_submount_lookup { 76 /** @count: Refcount */ 77 refcount_t count; 78 79 /** 80 * @nodeid: Unique ID, which identifies the inode between userspace 81 * and kernel 82 */ 83 u64 nodeid; 84 85 /** @forget: The request used for sending the FORGET message */ 86 struct fuse_forget_link *forget; 87 }; 88 89 /* Container for data related to mapping to backing file */ 90 struct fuse_backing { 91 struct file *file; 92 const struct cred *cred; 93 94 /* refcount */ 95 refcount_t count; 96 struct rcu_head rcu; 97 }; 98 99 /** 100 * struct fuse_inode - FUSE inode 101 */ 102 struct fuse_inode { 103 /** @inode: Inode data */ 104 struct inode inode; 105 106 /** 107 * @nodeid: Unique ID, which identifies the inode between userspace 108 * and kernel 109 */ 110 u64 nodeid; 111 112 /** @nlookup: Number of lookups on this inode */ 113 u64 nlookup; 114 115 /** @forget: The request used for sending the FORGET message */ 116 struct fuse_forget_link *forget; 117 118 /** @i_time: Time in jiffies until the file attributes are valid */ 119 u64 i_time; 120 121 /** @inval_mask: Which attributes are invalid */ 122 u32 inval_mask; 123 124 /** 125 * @orig_i_mode: The sticky bit in inode->i_mode may have been removed, 126 * so preserve the original mode 127 */ 128 umode_t orig_i_mode; 129 130 /** @i_btime: Cache birthtime */ 131 struct timespec64 i_btime; 132 133 /** @orig_ino: 64-bit inode number */ 134 u64 orig_ino; 135 136 /** @attr_version: Version of last attribute change */ 137 u64 attr_version; 138 139 union { 140 /* read/write io cache (regular file only) */ 141 struct { 142 /** 143 * @write_files: Files usable in writepage. 144 * Protected by fi->lock 145 */ 146 struct list_head write_files; 147 148 /** 149 * @queued_writes: Writepages pending on truncate or 150 * fsync 151 */ 152 struct list_head queued_writes; 153 154 /** 155 * @writectr: Number of sent writes, a negative bias 156 * (FUSE_NOWRITE) means more writes are blocked 157 */ 158 int writectr; 159 160 /** @iocachectr: Number of files/maps using page cache */ 161 int iocachectr; 162 163 /** @page_waitq: Waitq for writepage completion */ 164 wait_queue_head_t page_waitq; 165 166 /** @direct_io_waitq: waitq for direct-io completion */ 167 wait_queue_head_t direct_io_waitq; 168 }; 169 170 /** @rdc: readdir cache (directory only) */ 171 struct { 172 /** @cached: true if fully cached */ 173 bool cached; 174 175 /** @size: size of cache */ 176 loff_t size; 177 178 /** 179 * @pos: position at end of cache (position of next 180 * entry) 181 */ 182 loff_t pos; 183 184 /** @version: version of the cache */ 185 u64 version; 186 187 /** 188 * @mtime: modification time of directory when cache was 189 * started 190 */ 191 struct timespec64 mtime; 192 193 /** 194 * @epoch: epoch of fc when cache was started 195 */ 196 int epoch; 197 198 /** 199 * @iversion: iversion of directory when cache was 200 * started 201 */ 202 u64 iversion; 203 204 /** @lock: protects above fields */ 205 spinlock_t lock; 206 } rdc; 207 }; 208 209 /** @state: Miscellaneous bits describing inode state */ 210 unsigned long state; 211 212 /** 213 * @mutex: Lock for serializing lookup and readdir for back 214 * compatibility 215 */ 216 struct mutex mutex; 217 218 /** @lock: Lock to protect write-related fields */ 219 spinlock_t lock; 220 221 #ifdef CONFIG_FUSE_DAX 222 /** 223 * @dax: Dax specific inode data 224 */ 225 struct fuse_inode_dax *dax; 226 #endif 227 /** @submount_lookup: Submount specific lookup tracking */ 228 struct fuse_submount_lookup *submount_lookup; 229 #ifdef CONFIG_FUSE_PASSTHROUGH 230 /** @fb: Reference to backing file in passthrough mode */ 231 struct fuse_backing *fb; 232 #endif 233 234 /** 235 * @cached_i_blkbits: The underlying inode->i_blkbits value will not 236 * be modified, so preserve the blocksize specified by the server. 237 */ 238 u8 cached_i_blkbits; 239 }; 240 241 /** FUSE inode state bits */ 242 enum { 243 /** Advise readdirplus */ 244 FUSE_I_ADVISE_RDPLUS, 245 /** Initialized with readdirplus */ 246 FUSE_I_INIT_RDPLUS, 247 /** An operation changing file size is in progress */ 248 FUSE_I_SIZE_UNSTABLE, 249 /* Bad inode */ 250 FUSE_I_BAD, 251 /* Has btime */ 252 FUSE_I_BTIME, 253 /* Wants or already has page cache IO */ 254 FUSE_I_CACHE_IO_MODE, 255 /* 256 * Client has exclusive access to the inode, either because fs is local 257 * or the fuse server has an exclusive "lease" on distributed fs 258 */ 259 FUSE_I_EXCLUSIVE, 260 }; 261 262 struct fuse_conn; 263 struct fuse_mount; 264 union fuse_file_args; 265 266 /** 267 * struct fuse_file - FUSE-specific file data 268 */ 269 struct fuse_file { 270 /** @fm: Fuse connection for this file */ 271 struct fuse_mount *fm; 272 273 /** @args: Argument space reserved for open/release */ 274 union fuse_file_args *args; 275 276 /** @kh: Kernel file handle guaranteed to be unique */ 277 u64 kh; 278 279 /** @fh: File handle used by userspace */ 280 u64 fh; 281 282 /** @nodeid: Node id of this file */ 283 u64 nodeid; 284 285 /** @count: Refcount */ 286 refcount_t count; 287 288 /** @open_flags: FOPEN_* flags returned by open */ 289 u32 open_flags; 290 291 /** @write_entry: Entry on inode's write_files list */ 292 struct list_head write_entry; 293 294 /** @readdir: Readdir-related */ 295 struct { 296 /** @pos: Dir stream position */ 297 loff_t pos; 298 299 /** @cache_off: Offset in cache */ 300 loff_t cache_off; 301 302 /** @version: Version of cache we are reading */ 303 u64 version; 304 305 } readdir; 306 307 /** @polled_node: RB node to be linked on fuse_conn->polled_files */ 308 struct rb_node polled_node; 309 310 /** @poll_wait: Wait queue head for poll */ 311 wait_queue_head_t poll_wait; 312 313 /** @iomode: Does file hold a fi->iocachectr refcount? */ 314 enum { IOM_NONE, IOM_CACHED, IOM_UNCACHED } iomode; 315 316 #ifdef CONFIG_FUSE_PASSTHROUGH 317 /** @passthrough: Reference to backing file in passthrough mode */ 318 struct file *passthrough; 319 /** @cred: passthrough file credentials */ 320 const struct cred *cred; 321 #endif 322 323 /** @flock: Has flock been performed on this file? */ 324 bool flock:1; 325 }; 326 327 struct fuse_release_args { 328 struct fuse_args args; 329 struct fuse_release_in inarg; 330 struct inode *inode; 331 }; 332 333 union fuse_file_args { 334 /* Used during open() */ 335 struct fuse_open_out open_outarg; 336 /* Used during release() */ 337 struct fuse_release_args release_args; 338 }; 339 340 #define FUSE_ARGS(args) struct fuse_args args = {} 341 342 /** The request IO state (for asynchronous processing) */ 343 struct fuse_io_priv { 344 struct kref refcnt; 345 struct work_struct work; 346 int async; 347 spinlock_t lock; 348 unsigned reqs; 349 ssize_t bytes; 350 size_t size; 351 __u64 offset; 352 bool write; 353 bool should_dirty; 354 int err; 355 struct kiocb *iocb; 356 struct completion *done; 357 bool blocking; 358 }; 359 360 #define FUSE_IO_PRIV_SYNC(i) \ 361 { \ 362 .refcnt = KREF_INIT(1), \ 363 .async = 0, \ 364 .iocb = i, \ 365 } 366 367 enum fuse_dax_mode { 368 FUSE_DAX_INODE_DEFAULT, /* default */ 369 FUSE_DAX_ALWAYS, /* "-o dax=always" */ 370 FUSE_DAX_NEVER, /* "-o dax=never" */ 371 FUSE_DAX_INODE_USER, /* "-o dax=inode" */ 372 }; 373 374 static inline bool fuse_is_inode_dax_mode(enum fuse_dax_mode mode) 375 { 376 return mode == FUSE_DAX_INODE_DEFAULT || mode == FUSE_DAX_INODE_USER; 377 } 378 379 struct fuse_fs_context { 380 struct fuse_dev *fud; 381 unsigned int rootmode; 382 kuid_t user_id; 383 kgid_t group_id; 384 bool is_bdev:1; 385 bool rootmode_present:1; 386 bool user_id_present:1; 387 bool group_id_present:1; 388 bool default_permissions:1; 389 bool allow_other:1; 390 bool destroy:1; 391 bool no_control:1; 392 bool no_force_umount:1; 393 bool legacy_opts_show:1; 394 enum fuse_dax_mode dax_mode; 395 unsigned int max_read; 396 unsigned int blksize; 397 const char *subtype; 398 399 /* DAX device, may be NULL */ 400 struct dax_device *dax_dev; 401 }; 402 403 struct fuse_sync_bucket { 404 /* count is a possible scalability bottleneck */ 405 atomic_t count; 406 wait_queue_head_t waitq; 407 struct rcu_head rcu; 408 }; 409 410 /** 411 * struct fuse_conn - A Fuse connection. 412 * 413 * This structure is created, when the root filesystem is mounted, and 414 * is destroyed, when the client device is closed and the last 415 * fuse_mount is destroyed. 416 */ 417 struct fuse_conn { 418 /** 419 * @lock: Lock protecting: 420 * - polled_files 421 * - backing_files_map 422 * - curr_bucket 423 */ 424 spinlock_t lock; 425 426 /** @count: Refcount */ 427 refcount_t count; 428 429 /** @epoch: Current epoch for up-to-date dentries */ 430 atomic_t epoch; 431 432 /** @epoch_work: Used to invalidate dentries from old epochs */ 433 struct work_struct epoch_work; 434 435 /** @rcu: Used to delay freeing fuse_conn, making it safe */ 436 struct rcu_head rcu; 437 438 /** @user_id: The user id for this mount */ 439 kuid_t user_id; 440 441 /** @group_id: The group id for this mount */ 442 kgid_t group_id; 443 444 /** @pid_ns: The pid namespace for this mount */ 445 struct pid_namespace *pid_ns; 446 447 /** @user_ns: The user namespace for this mount */ 448 struct user_namespace *user_ns; 449 450 /** @max_read: Maximum read size */ 451 unsigned max_read; 452 453 /** @max_write: Maximum write size */ 454 unsigned max_write; 455 456 /** 457 * @max_pages: Maximum number of pages that can be used in a 458 * single request 459 */ 460 unsigned int max_pages; 461 462 /** 463 * @max_pages_limit: Constrain ->max_pages to this value during 464 * feature negotiation 465 */ 466 unsigned int max_pages_limit; 467 468 /** @chan: transport layer object */ 469 struct fuse_chan *chan; 470 471 /** @khctr: The next unique kernel file handle */ 472 atomic64_t khctr; 473 474 /** 475 * @polled_files: rbtree of fuse_files waiting for poll events 476 * indexed by ph 477 */ 478 struct rb_root polled_files; 479 480 /** 481 * @congestion_threshold: Number of background requests at which 482 * congestion starts 483 */ 484 unsigned congestion_threshold; 485 486 /** 487 * @conn_error: Connection failed (version mismatch). Cannot race with 488 * setting other bitfields since it is only set once in INIT 489 * reply, before any other request, and never cleared 490 */ 491 unsigned conn_error:1; 492 493 /** @conn_init: Connection successful. Only set in INIT */ 494 unsigned conn_init:1; 495 496 /** @async_read: Do readahead asynchronously? Only set in INIT */ 497 unsigned async_read:1; 498 499 /** 500 * @abort_err: Return an unique read error after abort. 501 * Only set in INIT 502 */ 503 unsigned abort_err:1; 504 505 /** 506 * @atomic_o_trunc: Do not send separate SETATTR request before 507 * open(O_TRUNC) 508 */ 509 unsigned atomic_o_trunc:1; 510 511 /** 512 * @export_support: Filesystem supports NFS exporting. 513 * Only set in INIT 514 */ 515 unsigned export_support:1; 516 517 /** @writeback_cache: write-back cache policy (default is write-through) */ 518 unsigned writeback_cache:1; 519 520 /** 521 * @parallel_dirops: allow parallel lookups and readdir (default is 522 * serialized) 523 */ 524 unsigned parallel_dirops:1; 525 526 /** 527 * @handle_killpriv: handle fs handles killing suid/sgid/cap on 528 * write/chown/trunc 529 */ 530 unsigned handle_killpriv:1; 531 532 /** @cache_symlinks: cache READLINK responses in page cache */ 533 unsigned cache_symlinks:1; 534 535 /** @legacy_opts_show: show legacy mount options */ 536 unsigned int legacy_opts_show:1; 537 538 /** 539 * @handle_killpriv_v2: 540 * fs kills suid/sgid/cap on write/chown/trunc. suid is killed on 541 * write/trunc only if caller did not have CAP_FSETID. sgid is killed 542 * on write/truncate only if caller did not have CAP_FSETID as well as 543 * file has group execute permission. 544 */ 545 unsigned handle_killpriv_v2:1; 546 547 /* 548 * The following bitfields are only for optimization purposes 549 * and hence races in setting them will not cause malfunction 550 */ 551 552 /** @no_open: Is open/release not implemented by fs? */ 553 unsigned no_open:1; 554 555 /** @no_opendir: Is opendir/releasedir not implemented by fs? */ 556 unsigned no_opendir:1; 557 558 /** @no_fsync: Is fsync not implemented by fs? */ 559 unsigned no_fsync:1; 560 561 /** @no_fsyncdir: Is fsyncdir not implemented by fs? */ 562 unsigned no_fsyncdir:1; 563 564 /** @no_flush: Is flush not implemented by fs? */ 565 unsigned no_flush:1; 566 567 /** @no_setxattr: Is setxattr not implemented by fs? */ 568 unsigned no_setxattr:1; 569 570 /** @setxattr_ext: Does file server support extended setxattr */ 571 unsigned setxattr_ext:1; 572 573 /** @no_getxattr: Is getxattr not implemented by fs? */ 574 unsigned no_getxattr:1; 575 576 /** @no_listxattr: Is listxattr not implemented by fs? */ 577 unsigned no_listxattr:1; 578 579 /** @no_removexattr: Is removexattr not implemented by fs? */ 580 unsigned no_removexattr:1; 581 582 /** @no_lock: Are posix file locking primitives not implemented by fs? */ 583 unsigned no_lock:1; 584 585 /** @no_access: Is access not implemented by fs? */ 586 unsigned no_access:1; 587 588 /** @no_create: Is create not implemented by fs? */ 589 unsigned no_create:1; 590 591 /** @no_bmap: Is bmap not implemented by fs? */ 592 unsigned no_bmap:1; 593 594 /** @no_poll: Is poll not implemented by fs? */ 595 unsigned no_poll:1; 596 597 /** @big_writes: Do multi-page cached writes */ 598 unsigned big_writes:1; 599 600 /** @dont_mask: Don't apply umask to creation modes */ 601 unsigned dont_mask:1; 602 603 /** @no_flock: Are BSD file locking primitives not implemented by fs? */ 604 unsigned no_flock:1; 605 606 /** @no_fallocate: Is fallocate not implemented by fs? */ 607 unsigned no_fallocate:1; 608 609 /** @no_rename2: Is rename with flags implemented by fs? */ 610 unsigned no_rename2:1; 611 612 /** @auto_inval_data: Use enhanced/automatic page cache invalidation. */ 613 unsigned auto_inval_data:1; 614 615 /** 616 * @explicit_inval_data: Filesystem is fully responsible for page cache 617 * invalidation. 618 */ 619 unsigned explicit_inval_data:1; 620 621 /** @do_readdirplus: Does the filesystem support readdirplus? */ 622 unsigned do_readdirplus:1; 623 624 /** @readdirplus_auto: Does the filesystem want adaptive readdirplus? */ 625 unsigned readdirplus_auto:1; 626 627 /** 628 * @async_dio: Does the filesystem support asynchronous direct-IO 629 * submission? 630 */ 631 unsigned async_dio:1; 632 633 /** @no_lseek: Is lseek not implemented by fs? */ 634 unsigned no_lseek:1; 635 636 /** @posix_acl: Does the filesystem support posix acls? */ 637 unsigned posix_acl:1; 638 639 /** 640 * @default_permissions: Check permissions based on the file mode 641 * or not? 642 */ 643 unsigned default_permissions:1; 644 645 /** 646 * @allow_other: Allow other than the mounter user to access the 647 * filesystem ? 648 */ 649 unsigned allow_other:1; 650 651 /** @no_copy_file_range: Does the filesystem support copy_file_range? */ 652 unsigned no_copy_file_range:1; 653 654 /** 655 * @no_copy_file_range_64: Does the filesystem support 656 * copy_file_range_64? 657 */ 658 unsigned no_copy_file_range_64:1; 659 660 /** @destroy: Send DESTROY request */ 661 unsigned int destroy:1; 662 663 /** @delete_stale: Delete dentries that have gone stale */ 664 unsigned int delete_stale:1; 665 666 /** @no_control: Do not create entry in fusectl fs */ 667 unsigned int no_control:1; 668 669 /** @no_force_umount: Do not allow MNT_FORCE umount */ 670 unsigned int no_force_umount:1; 671 672 /** @auto_submounts: Auto-mount submounts announced by the server */ 673 unsigned int auto_submounts:1; 674 675 /** @sync_fs: Propagate syncfs() to server */ 676 unsigned int sync_fs:1; 677 678 /** @init_security: Initialize security xattrs when creating a new inode */ 679 unsigned int init_security:1; 680 681 /** 682 * @create_supp_group: Add supplementary group info when creating 683 * a new inode 684 */ 685 unsigned int create_supp_group:1; 686 687 /** @inode_dax: Does the filesystem support per inode DAX? */ 688 unsigned int inode_dax:1; 689 690 /** @no_tmpfile: Is tmpfile not implemented by fs? */ 691 unsigned int no_tmpfile:1; 692 693 /** 694 * @direct_io_allow_mmap: Relax restrictions to allow shared mmap 695 * in FOPEN_DIRECT_IO mode 696 */ 697 unsigned int direct_io_allow_mmap:1; 698 699 /** @no_statx: Is statx not implemented by fs? */ 700 unsigned int no_statx:1; 701 702 /** @passthrough: Passthrough support for read/write IO */ 703 unsigned int passthrough:1; 704 705 /** @use_pages_for_kvec_io: Use pages instead of pointer for kernel I/O */ 706 unsigned int use_pages_for_kvec_io:1; 707 708 /** @no_link: Is link not implemented by fs? */ 709 unsigned int no_link:1; 710 711 /** @sync_init: Is synchronous FUSE_INIT allowed? */ 712 unsigned int sync_init:1; 713 714 /** @max_stack_depth: Maximum stack depth for passthrough backing files */ 715 int max_stack_depth; 716 717 /** @minor: Negotiated minor version */ 718 unsigned minor; 719 720 /** @entry: Entry on the fuse_conn_list */ 721 struct list_head entry; 722 723 /** @dev: Device ID from the root super block */ 724 dev_t dev; 725 726 /** @scramble_key: Key for lock owner ID scrambling */ 727 u32 scramble_key[4]; 728 729 /** @attr_version: Version counter for attribute changes */ 730 atomic64_t attr_version; 731 732 /** @evict_ctr: Version counter for evict inode */ 733 atomic64_t evict_ctr; 734 735 /** @name_max: maximum file name length */ 736 u32 name_max; 737 738 /** @release: Called on final put */ 739 void (*release)(struct fuse_conn *); 740 741 /** 742 * @killsb: Read/write semaphore to hold when accessing the sb of any 743 * fuse_mount belonging to this connection 744 */ 745 struct rw_semaphore killsb; 746 747 #ifdef CONFIG_FUSE_DAX 748 /** @dax_mode: Dax mode */ 749 enum fuse_dax_mode dax_mode; 750 751 /** @dax: Dax specific conn data, non-NULL if DAX is enabled */ 752 struct fuse_conn_dax *dax; 753 #endif 754 755 /** @mounts: List of filesystems using this connection */ 756 struct list_head mounts; 757 758 /** @curr_bucket: New writepages go into this bucket */ 759 struct fuse_sync_bucket __rcu *curr_bucket; 760 761 #ifdef CONFIG_FUSE_PASSTHROUGH 762 /** @backing_files_map: IDR for backing files ids */ 763 struct idr backing_files_map; 764 #endif 765 }; 766 767 /* 768 * Represents a mounted filesystem, potentially a submount. 769 * 770 * This object allows sharing a fuse_conn between separate mounts to 771 * allow submounts with dedicated superblocks and thus separate device 772 * IDs. 773 */ 774 struct fuse_mount { 775 /* Underlying (potentially shared) connection to the FUSE server */ 776 struct fuse_conn *fc; 777 778 /* 779 * Super block for this connection (fc->killsb must be held when 780 * accessing this). 781 */ 782 struct super_block *sb; 783 784 /* Entry on fc->mounts */ 785 struct list_head fc_entry; 786 struct rcu_head rcu; 787 }; 788 789 /* 790 * Empty header for FUSE opcodes without specific header needs. 791 * Used as a placeholder in args->in_args[0] for consistency 792 * across all FUSE operations, simplifying request handling. 793 */ 794 struct fuse_zero_header {}; 795 796 static inline void fuse_set_zero_arg0(struct fuse_args *args) 797 { 798 args->in_args[0].size = sizeof(struct fuse_zero_header); 799 args->in_args[0].value = NULL; 800 } 801 802 static inline struct fuse_mount *get_fuse_mount_super(struct super_block *sb) 803 { 804 return sb->s_fs_info; 805 } 806 807 static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb) 808 { 809 return get_fuse_mount_super(sb)->fc; 810 } 811 812 static inline struct fuse_mount *get_fuse_mount(struct inode *inode) 813 { 814 return get_fuse_mount_super(inode->i_sb); 815 } 816 817 static inline struct fuse_conn *get_fuse_conn(struct inode *inode) 818 { 819 return get_fuse_mount_super(inode->i_sb)->fc; 820 } 821 822 static inline struct fuse_inode *get_fuse_inode(const struct inode *inode) 823 { 824 return container_of(inode, struct fuse_inode, inode); 825 } 826 827 static inline u64 get_node_id(struct inode *inode) 828 { 829 return get_fuse_inode(inode)->nodeid; 830 } 831 832 static inline int invalid_nodeid(u64 nodeid) 833 { 834 return !nodeid || nodeid == FUSE_ROOT_ID; 835 } 836 837 static inline u64 fuse_get_attr_version(struct fuse_conn *fc) 838 { 839 return atomic64_read(&fc->attr_version); 840 } 841 842 static inline u64 fuse_get_evict_ctr(struct fuse_conn *fc) 843 { 844 return atomic64_read(&fc->evict_ctr); 845 } 846 847 static inline bool fuse_stale_inode(const struct inode *inode, int generation, 848 struct fuse_attr *attr) 849 { 850 return inode->i_generation != generation || 851 inode_wrong_type(inode, attr->mode); 852 } 853 854 static inline void fuse_make_bad(struct inode *inode) 855 { 856 set_bit(FUSE_I_BAD, &get_fuse_inode(inode)->state); 857 } 858 859 static inline bool fuse_is_bad(struct inode *inode) 860 { 861 return unlikely(test_bit(FUSE_I_BAD, &get_fuse_inode(inode)->state)); 862 } 863 864 static inline bool fuse_inode_is_exclusive(const struct inode *inode) 865 { 866 const struct fuse_inode *fi = get_fuse_inode(inode); 867 868 return test_bit(FUSE_I_EXCLUSIVE, &fi->state); 869 } 870 871 static inline struct folio **fuse_folios_alloc(unsigned int nfolios, gfp_t flags, 872 struct fuse_folio_desc **desc) 873 { 874 struct folio **folios; 875 876 folios = kzalloc(nfolios * (sizeof(struct folio *) + 877 sizeof(struct fuse_folio_desc)), flags); 878 *desc = (void *) (folios + nfolios); 879 880 return folios; 881 } 882 883 static inline void fuse_folio_descs_length_init(struct fuse_folio_desc *descs, 884 unsigned int index, 885 unsigned int nr_folios) 886 { 887 int i; 888 889 for (i = index; i < index + nr_folios; i++) 890 descs[i].length = PAGE_SIZE - descs[i].offset; 891 } 892 893 static inline void fuse_sync_bucket_dec(struct fuse_sync_bucket *bucket) 894 { 895 /* Need RCU protection to prevent use after free after the decrement */ 896 rcu_read_lock(); 897 if (atomic_dec_and_test(&bucket->count)) 898 wake_up(&bucket->waitq); 899 rcu_read_unlock(); 900 } 901 902 /** Device operations */ 903 extern const struct file_operations fuse_dev_operations; 904 905 extern const struct dentry_operations fuse_dentry_operations; 906 907 /* 908 * Get a filled in inode 909 */ 910 struct inode *fuse_iget(struct super_block *sb, u64 nodeid, 911 int generation, struct fuse_attr *attr, 912 u64 attr_valid, u64 attr_version, 913 u64 evict_ctr); 914 915 int fuse_lookup_name(struct super_block *sb, u64 nodeid, const struct qstr *name, 916 struct fuse_entry_out *outarg, struct inode **inode); 917 918 /* 919 * Initialize READ or READDIR request 920 */ 921 struct fuse_io_args { 922 union { 923 struct { 924 struct fuse_read_in in; 925 u64 attr_ver; 926 } read; 927 struct { 928 struct fuse_write_in in; 929 struct fuse_write_out out; 930 bool folio_locked; 931 } write; 932 }; 933 struct fuse_args_pages ap; 934 struct fuse_io_priv *io; 935 struct fuse_file *ff; 936 }; 937 938 void fuse_read_args_fill(struct fuse_io_args *ia, struct file *file, loff_t pos, 939 size_t count, int opcode); 940 941 942 struct fuse_file *fuse_file_alloc(struct fuse_mount *fm, bool release); 943 void fuse_file_free(struct fuse_file *ff); 944 int fuse_finish_open(struct inode *inode, struct file *file); 945 946 void fuse_sync_release(struct fuse_inode *fi, struct fuse_file *ff, 947 unsigned int flags); 948 949 /* 950 * Send RELEASE or RELEASEDIR request 951 */ 952 void fuse_release_common(struct file *file, bool isdir); 953 954 /* 955 * Send FSYNC or FSYNCDIR request 956 */ 957 int fuse_fsync_common(struct file *file, loff_t start, loff_t end, 958 int datasync, int opcode); 959 960 /* 961 * Notify poll wakeup 962 */ 963 int fuse_notify_poll_wakeup(struct fuse_conn *fc, 964 struct fuse_notify_poll_wakeup_out *outarg); 965 966 /* 967 * Initialize file operations on a regular file 968 */ 969 void fuse_init_file_inode(struct inode *inode, unsigned int flags); 970 971 /* 972 * Initialize inode operations on regular files and special files 973 */ 974 void fuse_init_common(struct inode *inode); 975 976 /* 977 * Initialize inode and file operations on a directory 978 */ 979 void fuse_init_dir(struct inode *inode); 980 981 /* 982 * Initialize inode operations on a symlink 983 */ 984 void fuse_init_symlink(struct inode *inode); 985 986 /* 987 * Change attributes of an inode 988 */ 989 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr, 990 struct fuse_statx *sx, 991 u64 attr_valid, u64 attr_version); 992 993 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr, 994 struct fuse_statx *sx, 995 u64 attr_valid, u32 cache_mask, 996 u64 evict_ctr); 997 998 u32 fuse_get_cache_mask(struct inode *inode); 999 1000 int fuse_ctl_init(void); 1001 void __exit fuse_ctl_cleanup(void); 1002 1003 /* 1004 * Simple request sending that does request allocation and freeing 1005 */ 1006 ssize_t __fuse_simple_request(struct mnt_idmap *idmap, 1007 struct fuse_mount *fm, 1008 struct fuse_args *args); 1009 1010 static inline ssize_t fuse_simple_request(struct fuse_mount *fm, struct fuse_args *args) 1011 { 1012 return __fuse_simple_request(&invalid_mnt_idmap, fm, args); 1013 } 1014 1015 static inline ssize_t fuse_simple_idmap_request(struct mnt_idmap *idmap, 1016 struct fuse_mount *fm, 1017 struct fuse_args *args) 1018 { 1019 return __fuse_simple_request(idmap, fm, args); 1020 } 1021 1022 int fuse_simple_background(struct fuse_mount *fm, struct fuse_args *args, 1023 gfp_t gfp_flags); 1024 int fuse_simple_notify_reply(struct fuse_mount *fm, struct fuse_args *args, u64 unique); 1025 1026 void fuse_dentry_tree_init(void); 1027 void fuse_dentry_tree_cleanup(void); 1028 1029 void fuse_epoch_work(struct work_struct *work); 1030 1031 /* 1032 * Invalidate inode attributes 1033 */ 1034 1035 /* Attributes possibly changed on data modification */ 1036 #define FUSE_STATX_MODIFY (STATX_MTIME | STATX_CTIME | STATX_BLOCKS) 1037 1038 /* Attributes possibly changed on data and/or size modification */ 1039 #define FUSE_STATX_MODSIZE (FUSE_STATX_MODIFY | STATX_SIZE) 1040 1041 /* Attributes possibly changed on directory modification */ 1042 #define FUSE_STATX_MODDIR (FUSE_STATX_MODSIZE | STATX_NLINK) 1043 1044 void fuse_invalidate_attr(struct inode *inode); 1045 void fuse_invalidate_attr_mask(struct inode *inode, u32 mask); 1046 1047 void fuse_invalidate_entry_cache(struct dentry *entry); 1048 1049 void fuse_invalidate_atime(struct inode *inode); 1050 1051 u64 fuse_time_to_jiffies(u64 sec, u32 nsec); 1052 #define ATTR_TIMEOUT(o) \ 1053 fuse_time_to_jiffies((o)->attr_valid, (o)->attr_valid_nsec) 1054 1055 void fuse_change_entry_timeout(struct dentry *entry, struct fuse_entry_out *o); 1056 1057 /* 1058 * Initialize fuse_conn 1059 */ 1060 void fuse_conn_init(struct fuse_conn *fc, struct fuse_mount *fm, 1061 struct user_namespace *user_ns, struct fuse_chan *fch); 1062 1063 int fuse_send_init(struct fuse_mount *fm); 1064 1065 /** 1066 * fuse_fill_super_common - Fill in superblock and initialize fuse connection 1067 * @sb: partially-initialized superblock to fill in 1068 * @ctx: mount context 1069 */ 1070 int fuse_fill_super_common(struct super_block *sb, struct fuse_fs_context *ctx); 1071 1072 /** 1073 * fuse_mount_remove - Remove the mount from the connection 1074 * @fm: fuse_mount to remove 1075 * 1076 * Returns: whether this was the last mount 1077 */ 1078 bool fuse_mount_remove(struct fuse_mount *fm); 1079 1080 /* 1081 * Setup context ops for submounts 1082 */ 1083 int fuse_init_fs_context_submount(struct fs_context *fsc); 1084 1085 /* 1086 * Shut down the connection (possibly sending DESTROY request). 1087 */ 1088 void fuse_conn_destroy(struct fuse_mount *fm); 1089 1090 /* Drop the connection and free the fuse mount */ 1091 void fuse_mount_destroy(struct fuse_mount *fm); 1092 1093 /** 1094 * fuse_ctl_add_conn - Add connection to control filesystem 1095 * @fc: Fuse connection to add 1096 */ 1097 int fuse_ctl_add_conn(struct fuse_conn *fc); 1098 1099 /** 1100 * fuse_ctl_remove_conn - Remove connection from control filesystem 1101 * @fc: Fuse connection to remove 1102 */ 1103 void fuse_ctl_remove_conn(struct fuse_conn *fc); 1104 1105 /* 1106 * Is file type valid? 1107 */ 1108 int fuse_valid_type(int m); 1109 1110 bool fuse_invalid_attr(struct fuse_attr *attr); 1111 1112 /* 1113 * Is current process allowed to perform filesystem operation? 1114 */ 1115 bool fuse_allow_current_process(struct fuse_conn *fc); 1116 1117 u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id); 1118 1119 void fuse_flush_time_update(struct inode *inode); 1120 void fuse_update_ctime(struct inode *inode); 1121 1122 int fuse_update_attributes(struct inode *inode, struct file *file, u32 mask); 1123 1124 void fuse_flush_writepages(struct inode *inode); 1125 1126 void fuse_set_nowrite(struct inode *inode); 1127 void fuse_release_nowrite(struct inode *inode); 1128 1129 /* 1130 * Scan all fuse_mounts belonging to fc to find the first where 1131 * ilookup5() returns a result. Return that result and the 1132 * respective fuse_mount in *fm (unless fm is NULL). 1133 * 1134 * The caller must hold fc->killsb. 1135 */ 1136 struct inode *fuse_ilookup(struct fuse_conn *fc, u64 nodeid, 1137 struct fuse_mount **fm); 1138 1139 /* 1140 * File-system tells the kernel to invalidate cache for the given node id. 1141 */ 1142 int fuse_reverse_inval_inode(struct fuse_conn *fc, u64 nodeid, 1143 loff_t offset, loff_t len); 1144 1145 /* 1146 * File-system tells the kernel to invalidate parent attributes and 1147 * the dentry matching parent/name. 1148 * 1149 * If the child_nodeid is non-zero and: 1150 * - matches the inode number for the dentry matching parent/name, 1151 * - is not a mount point 1152 * - is a file or oan empty directory 1153 * then the dentry is unhashed (d_delete()). 1154 */ 1155 int fuse_reverse_inval_entry(struct fuse_conn *fc, u64 parent_nodeid, 1156 u64 child_nodeid, struct qstr *name, u32 flags); 1157 1158 /* 1159 * Try to prune this inode. If neither the inode itself nor dentries associated 1160 * with this inode have any external reference, then the inode can be freed. 1161 */ 1162 void fuse_try_prune_one_inode(struct fuse_conn *fc, u64 nodeid); 1163 1164 int fuse_do_open(struct fuse_mount *fm, u64 nodeid, struct file *file, 1165 bool isdir); 1166 1167 /* 1168 * fuse_direct_io() flags 1169 */ 1170 1171 /** If set, it is WRITE; otherwise - READ */ 1172 #define FUSE_DIO_WRITE (1 << 0) 1173 1174 /** CUSE pass fuse_direct_io() a file which f_mapping->host is not from FUSE */ 1175 #define FUSE_DIO_CUSE (1 << 1) 1176 1177 ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter, 1178 loff_t *ppos, int flags); 1179 long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg, 1180 unsigned int flags); 1181 long fuse_ioctl_common(struct file *file, unsigned int cmd, 1182 unsigned long arg, unsigned int flags); 1183 __poll_t fuse_file_poll(struct file *file, poll_table *wait); 1184 1185 bool fuse_write_update_attr(struct inode *inode, loff_t pos, ssize_t written); 1186 1187 int fuse_flush_times(struct inode *inode, struct fuse_file *ff); 1188 int fuse_write_inode(struct inode *inode, struct writeback_control *wbc); 1189 1190 int fuse_do_setattr(struct mnt_idmap *idmap, struct dentry *dentry, 1191 struct iattr *attr, struct file *file); 1192 1193 void fuse_unlock_inode(struct inode *inode, bool locked); 1194 bool fuse_lock_inode(struct inode *inode); 1195 1196 int fuse_setxattr(struct inode *inode, const char *name, const void *value, 1197 size_t size, int flags, unsigned int extra_flags); 1198 ssize_t fuse_getxattr(struct inode *inode, const char *name, void *value, 1199 size_t size); 1200 ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size); 1201 int fuse_removexattr(struct inode *inode, const char *name); 1202 extern const struct xattr_handler * const fuse_xattr_handlers[]; 1203 1204 struct posix_acl; 1205 struct posix_acl *fuse_get_inode_acl(struct inode *inode, int type, bool rcu); 1206 struct posix_acl *fuse_get_acl(struct mnt_idmap *idmap, 1207 struct dentry *dentry, int type); 1208 int fuse_set_acl(struct mnt_idmap *, struct dentry *dentry, 1209 struct posix_acl *acl, int type); 1210 1211 /* readdir.c */ 1212 int fuse_readdir(struct file *file, struct dir_context *ctx); 1213 1214 void fuse_free_conn(struct fuse_conn *fc); 1215 1216 /* dax.c */ 1217 1218 #define FUSE_IS_DAX(inode) (IS_ENABLED(CONFIG_FUSE_DAX) && IS_DAX(inode)) 1219 1220 ssize_t fuse_dax_read_iter(struct kiocb *iocb, struct iov_iter *to); 1221 ssize_t fuse_dax_write_iter(struct kiocb *iocb, struct iov_iter *from); 1222 int fuse_dax_mmap(struct file *file, struct vm_area_struct *vma); 1223 int fuse_dax_break_layouts(struct inode *inode, u64 dmap_start, u64 dmap_end); 1224 int fuse_dax_conn_alloc(struct fuse_conn *fc, enum fuse_dax_mode mode, 1225 struct dax_device *dax_dev); 1226 void fuse_dax_conn_free(struct fuse_conn *fc); 1227 bool fuse_dax_inode_alloc(struct super_block *sb, struct fuse_inode *fi); 1228 void fuse_dax_inode_init(struct inode *inode, unsigned int flags); 1229 void fuse_dax_inode_cleanup(struct inode *inode); 1230 void fuse_dax_dontcache(struct inode *inode, unsigned int flags); 1231 bool fuse_dax_check_alignment(struct fuse_conn *fc, unsigned int map_alignment); 1232 void fuse_dax_cancel_work(struct fuse_conn *fc); 1233 1234 /* ioctl.c */ 1235 long fuse_file_ioctl(struct file *file, unsigned int cmd, unsigned long arg); 1236 long fuse_file_compat_ioctl(struct file *file, unsigned int cmd, 1237 unsigned long arg); 1238 int fuse_fileattr_get(struct dentry *dentry, struct file_kattr *fa); 1239 int fuse_fileattr_set(struct mnt_idmap *idmap, 1240 struct dentry *dentry, struct file_kattr *fa); 1241 1242 /* iomode.c */ 1243 int fuse_file_cached_io_open(struct inode *inode, struct fuse_file *ff); 1244 int fuse_inode_uncached_io_start(struct fuse_inode *fi, 1245 struct fuse_backing *fb); 1246 void fuse_inode_uncached_io_end(struct fuse_inode *fi); 1247 1248 int fuse_file_io_open(struct file *file, struct inode *inode); 1249 void fuse_file_io_release(struct fuse_file *ff, struct inode *inode); 1250 1251 /* file.c */ 1252 struct fuse_file *fuse_file_open(struct fuse_mount *fm, u64 nodeid, 1253 unsigned int open_flags, bool isdir); 1254 void fuse_file_release(struct inode *inode, struct fuse_file *ff, 1255 unsigned int open_flags, fl_owner_t id, bool isdir); 1256 1257 /* backing.c */ 1258 #ifdef CONFIG_FUSE_PASSTHROUGH 1259 struct fuse_backing *fuse_backing_get(struct fuse_backing *fb); 1260 void fuse_backing_put(struct fuse_backing *fb); 1261 struct fuse_backing *fuse_backing_lookup(struct fuse_conn *fc, int backing_id); 1262 #else 1263 1264 static inline struct fuse_backing *fuse_backing_get(struct fuse_backing *fb) 1265 { 1266 return NULL; 1267 } 1268 1269 static inline void fuse_backing_put(struct fuse_backing *fb) 1270 { 1271 } 1272 static inline struct fuse_backing *fuse_backing_lookup(struct fuse_conn *fc, 1273 int backing_id) 1274 { 1275 return NULL; 1276 } 1277 #endif 1278 1279 void fuse_backing_files_init(struct fuse_conn *fc); 1280 void fuse_backing_files_free(struct fuse_conn *fc); 1281 1282 /* passthrough.c */ 1283 static inline struct fuse_backing *fuse_inode_backing(struct fuse_inode *fi) 1284 { 1285 #ifdef CONFIG_FUSE_PASSTHROUGH 1286 return READ_ONCE(fi->fb); 1287 #else 1288 return NULL; 1289 #endif 1290 } 1291 1292 static inline struct fuse_backing *fuse_inode_backing_set(struct fuse_inode *fi, 1293 struct fuse_backing *fb) 1294 { 1295 #ifdef CONFIG_FUSE_PASSTHROUGH 1296 return xchg(&fi->fb, fb); 1297 #else 1298 return NULL; 1299 #endif 1300 } 1301 1302 struct fuse_backing *fuse_passthrough_open(struct file *file, int backing_id); 1303 void fuse_passthrough_release(struct fuse_file *ff, struct fuse_backing *fb); 1304 1305 static inline struct file *fuse_file_passthrough(struct fuse_file *ff) 1306 { 1307 #ifdef CONFIG_FUSE_PASSTHROUGH 1308 return ff->passthrough; 1309 #else 1310 return NULL; 1311 #endif 1312 } 1313 1314 ssize_t fuse_passthrough_read_iter(struct kiocb *iocb, struct iov_iter *iter); 1315 ssize_t fuse_passthrough_write_iter(struct kiocb *iocb, struct iov_iter *iter); 1316 ssize_t fuse_passthrough_splice_read(struct file *in, loff_t *ppos, 1317 struct pipe_inode_info *pipe, 1318 size_t len, unsigned int flags); 1319 ssize_t fuse_passthrough_splice_write(struct pipe_inode_info *pipe, 1320 struct file *out, loff_t *ppos, 1321 size_t len, unsigned int flags); 1322 ssize_t fuse_passthrough_mmap(struct file *file, struct vm_area_struct *vma); 1323 1324 #ifdef CONFIG_SYSCTL 1325 extern int fuse_sysctl_register(void); 1326 extern void fuse_sysctl_unregister(void); 1327 #else 1328 #define fuse_sysctl_register() (0) 1329 #define fuse_sysctl_unregister() do { } while (0) 1330 #endif /* CONFIG_SYSCTL */ 1331 1332 #endif /* _FS_FUSE_I_H */ 1333