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/android_fuse.h>
17 #include <linux/filter.h>
18 #include <linux/pagemap.h>
19 #include <linux/fuse.h>
20 #include <linux/fs.h>
21 #include <linux/mount.h>
22 #include <linux/wait.h>
23 #include <linux/list.h>
24 #include <linux/spinlock.h>
25 #include <linux/mm.h>
26 #include <linux/backing-dev.h>
27 #include <linux/mutex.h>
28 #include <linux/rwsem.h>
29 #include <linux/rbtree.h>
30 #include <linux/poll.h>
31 #include <linux/workqueue.h>
32 #include <linux/kref.h>
33 #include <linux/xattr.h>
34 #include <linux/pid_namespace.h>
35 #include <linux/refcount.h>
36 #include <linux/user_namespace.h>
37 #include <linux/statfs.h>
38 
39 #define FUSE_SUPER_MAGIC 0x65735546
40 
41 /** Default max number of pages that can be used in a single read request */
42 #define FUSE_DEFAULT_MAX_PAGES_PER_REQ 32
43 
44 /** Maximum of max_pages received in init_out */
45 #define FUSE_MAX_MAX_PAGES 256
46 
47 /** Bias for fi->writectr, meaning new writepages must not be sent */
48 #define FUSE_NOWRITE INT_MIN
49 
50 /** It could be as large as PATH_MAX, but would that have any uses? */
51 #define FUSE_NAME_MAX 1024
52 
53 /** Number of dentries for each connection in the control filesystem */
54 #define FUSE_CTL_NUM_DENTRIES 5
55 
56 /** List of active connections */
57 extern struct list_head fuse_conn_list;
58 
59 /** Global mutex protecting fuse_conn_list and the control filesystem */
60 extern struct mutex fuse_mutex;
61 
62 /** Module parameters */
63 extern unsigned max_user_bgreq;
64 extern unsigned max_user_congthresh;
65 
66 /* One forget request */
67 struct fuse_forget_link {
68 	struct fuse_forget_one forget_one;
69 	struct fuse_forget_link *next;
70 };
71 
72 
73 /* Submount lookup tracking */
74 struct fuse_submount_lookup {
75 	/** Refcount */
76 	refcount_t count;
77 
78 	/** Unique ID, which identifies the inode between userspace
79 	 * and kernel */
80 	u64 nodeid;
81 
82 	/** The request used for sending the FORGET message */
83 	struct fuse_forget_link *forget;
84 };
85 
86 /** Container for data related to mapping to backing file */
87 struct fuse_backing {
88 	struct file *file;
89 	struct cred *cred;
90 
91 	/** refcount */
92 	refcount_t count;
93 	struct rcu_head rcu;
94 };
95 
96 /** FUSE specific dentry data */
97 #if BITS_PER_LONG < 64 || defined(CONFIG_FUSE_BPF)
98 struct fuse_dentry {
99 	union {
100 		u64 time;
101 		struct rcu_head rcu;
102 	};
103 
104 #ifdef CONFIG_FUSE_BPF
105 	struct path backing_path;
106 
107 	/* bpf program *only* set for negative dentries */
108 	struct bpf_prog *bpf;
109 #endif
110 };
111 
get_fuse_dentry(const struct dentry * entry)112 static inline struct fuse_dentry *get_fuse_dentry(const struct dentry *entry)
113 {
114 	return entry->d_fsdata;
115 }
116 #endif
117 
118 #ifdef CONFIG_FUSE_BPF
get_fuse_backing_path(const struct dentry * d,struct path * path)119 static inline void get_fuse_backing_path(const struct dentry *d,
120 					  struct path *path)
121 {
122 	struct fuse_dentry *di = get_fuse_dentry(d);
123 
124 	if (!di) {
125 		*path = (struct path) {};
126 		return;
127 	}
128 
129 	*path = di->backing_path;
130 	path_get(path);
131 }
132 #endif
133 
134 /** FUSE inode */
135 struct fuse_inode {
136 	/** Inode data */
137 	struct inode inode;
138 
139 #ifdef CONFIG_FUSE_BPF
140 	/**
141 	 * Backing inode, if this inode is from a backing file system.
142 	 * If this is set, nodeid is 0.
143 	 */
144 	struct inode *backing_inode;
145 
146 	/**
147 	 * bpf_prog, run on all operations to determine whether to pass through
148 	 * or handle in place
149 	 */
150 	struct bpf_prog *bpf;
151 #endif
152 
153 	/** Unique ID, which identifies the inode between userspace
154 	 * and kernel */
155 	u64 nodeid;
156 
157 	/** Number of lookups on this inode */
158 	u64 nlookup;
159 
160 	/** The request used for sending the FORGET message */
161 	struct fuse_forget_link *forget;
162 
163 	/** Time in jiffies until the file attributes are valid */
164 	u64 i_time;
165 
166 	/* Which attributes are invalid */
167 	u32 inval_mask;
168 
169 	/** The sticky bit in inode->i_mode may have been removed, so
170 	    preserve the original mode */
171 	umode_t orig_i_mode;
172 
173 	/* Cache birthtime */
174 	struct timespec64 i_btime;
175 
176 	/** 64 bit inode number */
177 	u64 orig_ino;
178 
179 	/** Version of last attribute change */
180 	u64 attr_version;
181 
182 	union {
183 		/* read/write io cache (regular file only) */
184 		struct {
185 			/* Files usable in writepage.  Protected by fi->lock */
186 			struct list_head write_files;
187 
188 			/* Writepages pending on truncate or fsync */
189 			struct list_head queued_writes;
190 
191 			/* Number of sent writes, a negative bias
192 			 * (FUSE_NOWRITE) means more writes are blocked */
193 			int writectr;
194 
195 			/** Number of files/maps using page cache */
196 			int iocachectr;
197 
198 			/* Number of files using passthrough */
199 			int iopassctr;
200 
201 			/* Waitq for writepage completion */
202 			wait_queue_head_t page_waitq;
203 
204 			/* waitq for direct-io completion */
205 			wait_queue_head_t direct_io_waitq;
206 
207 			/* List of writepage requestst (pending or sent) */
208 			struct rb_root writepages;
209 		};
210 
211 		/* readdir cache (directory only) */
212 		struct {
213 			/* true if fully cached */
214 			bool cached;
215 
216 			/* size of cache */
217 			loff_t size;
218 
219 			/* position at end of cache (position of next entry) */
220 			loff_t pos;
221 
222 			/* version of the cache */
223 			u64 version;
224 
225 			/* modification time of directory when cache was
226 			 * started */
227 			struct timespec64 mtime;
228 
229 			/* iversion of directory when cache was started */
230 			u64 iversion;
231 
232 			/* protects above fields */
233 			spinlock_t lock;
234 		} rdc;
235 	};
236 
237 	/** Miscellaneous bits describing inode state */
238 	unsigned long state;
239 
240 	/** Lock for serializing lookup and readdir for back compatibility*/
241 	struct mutex mutex;
242 
243 	/** Lock to protect write related fields */
244 	spinlock_t lock;
245 
246 #ifdef CONFIG_FUSE_DAX
247 	/*
248 	 * Dax specific inode data
249 	 */
250 	struct fuse_inode_dax *dax;
251 #endif
252 	/** Submount specific lookup tracking */
253 	struct fuse_submount_lookup *submount_lookup;
254 #ifdef CONFIG_FUSE_PASSTHROUGH
255 	/** Reference to backing file in passthrough mode */
256 	struct fuse_backing *fb;
257 #endif
258 };
259 
260 /** FUSE inode state bits */
261 enum {
262 	/** Advise readdirplus  */
263 	FUSE_I_ADVISE_RDPLUS,
264 	/** Initialized with readdirplus */
265 	FUSE_I_INIT_RDPLUS,
266 	/** An operation changing file size is in progress  */
267 	FUSE_I_SIZE_UNSTABLE,
268 	/* Bad inode */
269 	FUSE_I_BAD,
270 	/* Has btime */
271 	FUSE_I_BTIME,
272 	/* Wants or already has page cache IO */
273 	FUSE_I_CACHE_IO_MODE,
274 };
275 
276 struct fuse_conn;
277 struct fuse_mount;
278 union fuse_file_args;
279 
280 /** FUSE specific file data */
281 struct fuse_file {
282 	/** Fuse connection for this file */
283 	struct fuse_mount *fm;
284 
285 	/* Argument space reserved for open/release */
286 	union fuse_file_args *args;
287 
288 	/** Kernel file handle guaranteed to be unique */
289 	u64 kh;
290 
291 	/** File handle used by userspace */
292 	u64 fh;
293 
294 	/** Node id of this file */
295 	u64 nodeid;
296 
297 	/** Refcount */
298 	refcount_t count;
299 
300 	/** FOPEN_* flags returned by open */
301 	u32 open_flags;
302 
303 	/** Entry on inode's write_files list */
304 	struct list_head write_entry;
305 
306 	/* Readdir related */
307 	struct {
308 		/* Dir stream position */
309 		loff_t pos;
310 
311 		/* Offset in cache */
312 		loff_t cache_off;
313 
314 		/* Version of cache we are reading */
315 		u64 version;
316 
317 	} readdir;
318 
319 #ifdef CONFIG_FUSE_BPF
320 	/**
321 	 * TODO: Reconcile with passthrough file
322 	 * backing file when in bpf mode
323 	 */
324 	struct file *backing_file;
325 #endif
326 
327 	/** RB node to be linked on fuse_conn->polled_files */
328 	struct rb_node polled_node;
329 
330 	/** Wait queue head for poll */
331 	wait_queue_head_t poll_wait;
332 
333 	/** Does file hold a fi->iocachectr refcount? */
334 	enum { IOM_NONE, IOM_CACHED, IOM_UNCACHED, IOM_PASSTHROUGH } iomode;
335 
336 #ifdef CONFIG_FUSE_PASSTHROUGH
337 	/** Reference to backing file in passthrough mode */
338 	struct file *passthrough;
339 	const struct cred *cred;
340 #endif
341 
342 	/** Has flock been performed on this file? */
343 	bool flock:1;
344 };
345 
346 /** One input argument of a request */
347 struct fuse_in_arg {
348 	unsigned size;
349 	const void *value;
350 };
351 
352 /** One output argument of a request */
353 struct fuse_arg {
354 	unsigned size;
355 	void *value;
356 };
357 
358 /** FUSE page descriptor */
359 struct fuse_page_desc {
360 	unsigned int length;
361 	unsigned int offset;
362 };
363 
364 struct fuse_args {
365 	uint64_t nodeid;
366 	uint32_t opcode;
367 	uint32_t error_in;
368 	uint8_t in_numargs;
369 	uint8_t out_numargs;
370 	uint8_t ext_idx;
371 	bool force:1;
372 	bool noreply:1;
373 	bool nocreds:1;
374 	bool in_pages:1;
375 	bool out_pages:1;
376 	bool user_pages:1;
377 	bool out_argvar:1;
378 	bool page_zeroing:1;
379 	bool page_replace:1;
380 	bool may_block:1;
381 	bool is_ext:1;
382 	bool is_pinned:1;
383 	bool invalidate_vmap:1;
384 	struct fuse_in_arg in_args[FUSE_MAX_IN_ARGS];
385 	struct fuse_arg out_args[FUSE_MAX_OUT_ARGS];
386 	void (*end)(struct fuse_mount *fm, struct fuse_args *args, int error);
387 	/* Used for kvec iter backed by vmalloc address */
388 	void *vmap_base;
389 
390 	/* Path used for completing d_canonical_path */
391 	struct path *canonical_path;
392 };
393 
394 struct fuse_args_pages {
395 	struct fuse_args args;
396 	struct page **pages;
397 	struct fuse_page_desc *descs;
398 	unsigned int num_pages;
399 };
400 
401 struct fuse_release_args {
402 	struct fuse_args args;
403 	struct fuse_release_in inarg;
404 	struct inode *inode;
405 };
406 
407 union fuse_file_args {
408 	/* Used during open() */
409 	struct fuse_open_out open_outarg;
410 	/* Used during release() */
411 	struct fuse_release_args release_args;
412 };
413 
414 #define FUSE_ARGS(args) struct fuse_args args = {}
415 
416 /** The request IO state (for asynchronous processing) */
417 struct fuse_io_priv {
418 	struct kref refcnt;
419 	int async;
420 	spinlock_t lock;
421 	unsigned reqs;
422 	ssize_t bytes;
423 	size_t size;
424 	__u64 offset;
425 	bool write;
426 	bool should_dirty;
427 	int err;
428 	struct kiocb *iocb;
429 	struct completion *done;
430 	bool blocking;
431 };
432 
433 #define FUSE_IO_PRIV_SYNC(i) \
434 {					\
435 	.refcnt = KREF_INIT(1),		\
436 	.async = 0,			\
437 	.iocb = i,			\
438 }
439 
440 /**
441  * Request flags
442  *
443  * FR_ISREPLY:		set if the request has reply
444  * FR_FORCE:		force sending of the request even if interrupted
445  * FR_BACKGROUND:	request is sent in the background
446  * FR_WAITING:		request is counted as "waiting"
447  * FR_ABORTED:		the request was aborted
448  * FR_INTERRUPTED:	the request has been interrupted
449  * FR_LOCKED:		data is being copied to/from the request
450  * FR_PENDING:		request is not yet in userspace
451  * FR_SENT:		request is in userspace, waiting for an answer
452  * FR_FINISHED:		request is finished
453  * FR_PRIVATE:		request is on private list
454  * FR_ASYNC:		request is asynchronous
455  */
456 enum fuse_req_flag {
457 	FR_ISREPLY,
458 	FR_FORCE,
459 	FR_BACKGROUND,
460 	FR_WAITING,
461 	FR_ABORTED,
462 	FR_INTERRUPTED,
463 	FR_LOCKED,
464 	FR_PENDING,
465 	FR_SENT,
466 	FR_FINISHED,
467 	FR_PRIVATE,
468 	FR_ASYNC,
469 };
470 
471 /**
472  * A request to the client
473  *
474  * .waitq.lock protects the following fields:
475  *   - FR_ABORTED
476  *   - FR_LOCKED (may also be modified under fc->lock, tested under both)
477  */
478 struct fuse_req {
479 	/** This can be on either pending processing or io lists in
480 	    fuse_conn */
481 	struct list_head list;
482 
483 	/** Entry on the interrupts list  */
484 	struct list_head intr_entry;
485 
486 	/* Input/output arguments */
487 	struct fuse_args *args;
488 
489 	/** refcount */
490 	refcount_t count;
491 
492 	/* Request flags, updated with test/set/clear_bit() */
493 	unsigned long flags;
494 
495 	/* The request input header */
496 	struct {
497 		struct fuse_in_header h;
498 	} in;
499 
500 	/* The request output header */
501 	struct {
502 		struct fuse_out_header h;
503 	} out;
504 
505 	/** Used to wake up the task waiting for completion of request*/
506 	wait_queue_head_t waitq;
507 
508 #if IS_ENABLED(CONFIG_VIRTIO_FS)
509 	/** virtio-fs's physically contiguous buffer for in and out args */
510 	void *argbuf;
511 #endif
512 
513 	/** fuse_mount this request belongs to */
514 	struct fuse_mount *fm;
515 };
516 
517 struct fuse_iqueue;
518 
519 /**
520  * Input queue callbacks
521  *
522  * Input queue signalling is device-specific.  For example, the /dev/fuse file
523  * uses fiq->waitq and fasync to wake processes that are waiting on queue
524  * readiness.  These callbacks allow other device types to respond to input
525  * queue activity.
526  */
527 struct fuse_iqueue_ops {
528 	/**
529 	 * Send one forget
530 	 */
531 	void (*send_forget)(struct fuse_iqueue *fiq, struct fuse_forget_link *link, bool sync);
532 
533 	/**
534 	 * Send interrupt for request
535 	 */
536 	void (*send_interrupt)(struct fuse_iqueue *fiq, struct fuse_req *req, bool sync);
537 
538 	/**
539 	 * Send one request
540 	 */
541 	void (*send_req)(struct fuse_iqueue *fiq, struct fuse_req *req, bool sync);
542 
543 	/**
544 	 * Clean up when fuse_iqueue is destroyed
545 	 */
546 	void (*release)(struct fuse_iqueue *fiq);
547 };
548 
549 /** /dev/fuse input queue operations */
550 extern const struct fuse_iqueue_ops fuse_dev_fiq_ops;
551 
552 struct fuse_iqueue {
553 	/** Connection established */
554 	unsigned connected;
555 
556 	/** Lock protecting accesses to members of this structure */
557 	spinlock_t lock;
558 
559 	/** Readers of the connection are waiting on this */
560 	wait_queue_head_t waitq;
561 
562 	/** The next unique request id */
563 	u64 reqctr;
564 
565 	/** The list of pending requests */
566 	struct list_head pending;
567 
568 	/** Pending interrupts */
569 	struct list_head interrupts;
570 
571 	/** Queue of pending forgets */
572 	struct fuse_forget_link forget_list_head;
573 	struct fuse_forget_link *forget_list_tail;
574 
575 	/** Batching of FORGET requests (positive indicates FORGET batch) */
576 	int forget_batch;
577 
578 	/** O_ASYNC requests */
579 	struct fasync_struct *fasync;
580 
581 	/** Device-specific callbacks */
582 	const struct fuse_iqueue_ops *ops;
583 
584 	/** Device-specific state */
585 	void *priv;
586 };
587 
588 #define FUSE_PQ_HASH_BITS 8
589 #define FUSE_PQ_HASH_SIZE (1 << FUSE_PQ_HASH_BITS)
590 
591 struct fuse_pqueue {
592 	/** Connection established */
593 	unsigned connected;
594 
595 	/** Lock protecting accessess to  members of this structure */
596 	spinlock_t lock;
597 
598 	/** Hash table of requests being processed */
599 	struct list_head *processing;
600 
601 	/** The list of requests under I/O */
602 	struct list_head io;
603 };
604 
605 /**
606  * Fuse device instance
607  */
608 struct fuse_dev {
609 	/** Fuse connection for this device */
610 	struct fuse_conn *fc;
611 
612 	/** Processing queue */
613 	struct fuse_pqueue pq;
614 
615 	/** list entry on fc->devices */
616 	struct list_head entry;
617 };
618 
619 enum fuse_dax_mode {
620 	FUSE_DAX_INODE_DEFAULT,	/* default */
621 	FUSE_DAX_ALWAYS,	/* "-o dax=always" */
622 	FUSE_DAX_NEVER,		/* "-o dax=never" */
623 	FUSE_DAX_INODE_USER,	/* "-o dax=inode" */
624 };
625 
fuse_is_inode_dax_mode(enum fuse_dax_mode mode)626 static inline bool fuse_is_inode_dax_mode(enum fuse_dax_mode mode)
627 {
628 	return mode == FUSE_DAX_INODE_DEFAULT || mode == FUSE_DAX_INODE_USER;
629 }
630 
631 struct fuse_fs_context {
632 	int fd;
633 	struct file *file;
634 	unsigned int rootmode;
635 	kuid_t user_id;
636 	kgid_t group_id;
637 	bool is_bdev:1;
638 	bool fd_present:1;
639 	bool rootmode_present:1;
640 	bool user_id_present:1;
641 	bool group_id_present:1;
642 	bool default_permissions:1;
643 	bool allow_other:1;
644 	bool destroy:1;
645 	bool no_control:1;
646 	bool no_force_umount:1;
647 	bool legacy_opts_show:1;
648 	enum fuse_dax_mode dax_mode;
649 	bool no_daemon:1;
650 	unsigned int max_read;
651 	unsigned int blksize;
652 	const char *subtype;
653 	struct bpf_prog *root_bpf;
654 	struct file *root_dir;
655 
656 	/* DAX device, may be NULL */
657 	struct dax_device *dax_dev;
658 
659 	/* fuse_dev pointer to fill in, should contain NULL on entry */
660 	void **fudptr;
661 };
662 
663 struct fuse_sync_bucket {
664 	/* count is a possible scalability bottleneck */
665 	atomic_t count;
666 	wait_queue_head_t waitq;
667 	struct rcu_head rcu;
668 };
669 
670 /**
671  * A Fuse connection.
672  *
673  * This structure is created, when the root filesystem is mounted, and
674  * is destroyed, when the client device is closed and the last
675  * fuse_mount is destroyed.
676  */
677 struct fuse_conn {
678 	/** Lock protecting accessess to  members of this structure */
679 	spinlock_t lock;
680 
681 	/** Refcount */
682 	refcount_t count;
683 
684 	/** Number of fuse_dev's */
685 	atomic_t dev_count;
686 
687 	struct rcu_head rcu;
688 
689 	/** The user id for this mount */
690 	kuid_t user_id;
691 
692 	/** The group id for this mount */
693 	kgid_t group_id;
694 
695 	/** The pid namespace for this mount */
696 	struct pid_namespace *pid_ns;
697 
698 	/** The user namespace for this mount */
699 	struct user_namespace *user_ns;
700 
701 	/** Maximum read size */
702 	unsigned max_read;
703 
704 	/** Maximum write size */
705 	unsigned max_write;
706 
707 	/** Maximum number of pages that can be used in a single request */
708 	unsigned int max_pages;
709 
710 	/** Constrain ->max_pages to this value during feature negotiation */
711 	unsigned int max_pages_limit;
712 
713 	/** Input queue */
714 	struct fuse_iqueue iq;
715 
716 	/** The next unique kernel file handle */
717 	atomic64_t khctr;
718 
719 	/** rbtree of fuse_files waiting for poll events indexed by ph */
720 	struct rb_root polled_files;
721 
722 	/** Maximum number of outstanding background requests */
723 	unsigned max_background;
724 
725 	/** Number of background requests at which congestion starts */
726 	unsigned congestion_threshold;
727 
728 	/** Number of requests currently in the background */
729 	unsigned num_background;
730 
731 	/** Number of background requests currently queued for userspace */
732 	unsigned active_background;
733 
734 	/** The list of background requests set aside for later queuing */
735 	struct list_head bg_queue;
736 
737 	/** Protects: max_background, congestion_threshold, num_background,
738 	 * active_background, bg_queue, blocked */
739 	spinlock_t bg_lock;
740 
741 	/** Flag indicating that INIT reply has been received. Allocating
742 	 * any fuse request will be suspended until the flag is set */
743 	int initialized;
744 
745 	/** Flag indicating if connection is blocked.  This will be
746 	    the case before the INIT reply is received, and if there
747 	    are too many outstading backgrounds requests */
748 	int blocked;
749 
750 	/** waitq for blocked connection */
751 	wait_queue_head_t blocked_waitq;
752 
753 	/** Connection established, cleared on umount, connection
754 	    abort and device release */
755 	unsigned connected;
756 
757 	/** Connection aborted via sysfs */
758 	bool aborted;
759 
760 	/** Connection failed (version mismatch).  Cannot race with
761 	    setting other bitfields since it is only set once in INIT
762 	    reply, before any other request, and never cleared */
763 	unsigned conn_error:1;
764 
765 	/** Connection successful.  Only set in INIT */
766 	unsigned conn_init:1;
767 
768 	/** Do readahead asynchronously?  Only set in INIT */
769 	unsigned async_read:1;
770 
771 	/** Return an unique read error after abort.  Only set in INIT */
772 	unsigned abort_err:1;
773 
774 	/** Do not send separate SETATTR request before open(O_TRUNC)  */
775 	unsigned atomic_o_trunc:1;
776 
777 	/** Filesystem supports NFS exporting.  Only set in INIT */
778 	unsigned export_support:1;
779 
780 	/** write-back cache policy (default is write-through) */
781 	unsigned writeback_cache:1;
782 
783 	/** allow parallel lookups and readdir (default is serialized) */
784 	unsigned parallel_dirops:1;
785 
786 	/** handle fs handles killing suid/sgid/cap on write/chown/trunc */
787 	unsigned handle_killpriv:1;
788 
789 	/** cache READLINK responses in page cache */
790 	unsigned cache_symlinks:1;
791 
792 	/* show legacy mount options */
793 	unsigned int legacy_opts_show:1;
794 
795 	/*
796 	 * fs kills suid/sgid/cap on write/chown/trunc. suid is killed on
797 	 * write/trunc only if caller did not have CAP_FSETID.  sgid is killed
798 	 * on write/truncate only if caller did not have CAP_FSETID as well as
799 	 * file has group execute permission.
800 	 */
801 	unsigned handle_killpriv_v2:1;
802 
803 	/*
804 	 * The following bitfields are only for optimization purposes
805 	 * and hence races in setting them will not cause malfunction
806 	 */
807 
808 	/** Is open/release not implemented by fs? */
809 	unsigned no_open:1;
810 
811 	/** Is opendir/releasedir not implemented by fs? */
812 	unsigned no_opendir:1;
813 
814 	/** Is fsync not implemented by fs? */
815 	unsigned no_fsync:1;
816 
817 	/** Is fsyncdir not implemented by fs? */
818 	unsigned no_fsyncdir:1;
819 
820 	/** Is flush not implemented by fs? */
821 	unsigned no_flush:1;
822 
823 	/** Is setxattr not implemented by fs? */
824 	unsigned no_setxattr:1;
825 
826 	/** Does file server support extended setxattr */
827 	unsigned setxattr_ext:1;
828 
829 	/** Is getxattr not implemented by fs? */
830 	unsigned no_getxattr:1;
831 
832 	/** Is listxattr not implemented by fs? */
833 	unsigned no_listxattr:1;
834 
835 	/** Is removexattr not implemented by fs? */
836 	unsigned no_removexattr:1;
837 
838 	/** Are posix file locking primitives not implemented by fs? */
839 	unsigned no_lock:1;
840 
841 	/** Is access not implemented by fs? */
842 	unsigned no_access:1;
843 
844 	/** Is create not implemented by fs? */
845 	unsigned no_create:1;
846 
847 	/** Is interrupt not implemented by fs? */
848 	unsigned no_interrupt:1;
849 
850 	/** Is bmap not implemented by fs? */
851 	unsigned no_bmap:1;
852 
853 	/** Is dentry_canonical_path not implemented by fs? */
854 	unsigned no_dentry_canonical_path:1;
855 
856 	/** Is poll not implemented by fs? */
857 	unsigned no_poll:1;
858 
859 	/** Do multi-page cached writes */
860 	unsigned big_writes:1;
861 
862 	/** Don't apply umask to creation modes */
863 	unsigned dont_mask:1;
864 
865 	/** Are BSD file locking primitives not implemented by fs? */
866 	unsigned no_flock:1;
867 
868 	/** Is fallocate not implemented by fs? */
869 	unsigned no_fallocate:1;
870 
871 	/** Is rename with flags implemented by fs? */
872 	unsigned no_rename2:1;
873 
874 	/** Use enhanced/automatic page cache invalidation. */
875 	unsigned auto_inval_data:1;
876 
877 	/** Filesystem is fully responsible for page cache invalidation. */
878 	unsigned explicit_inval_data:1;
879 
880 	/** Does the filesystem support readdirplus? */
881 	unsigned do_readdirplus:1;
882 
883 	/** Does the filesystem want adaptive readdirplus? */
884 	unsigned readdirplus_auto:1;
885 
886 	/** Does the filesystem support asynchronous direct-IO submission? */
887 	unsigned async_dio:1;
888 
889 	/** Is lseek not implemented by fs? */
890 	unsigned no_lseek:1;
891 
892 	/** Does the filesystem support posix acls? */
893 	unsigned posix_acl:1;
894 
895 	/** Check permissions based on the file mode or not? */
896 	unsigned default_permissions:1;
897 
898 	/** Allow other than the mounter user to access the filesystem ? */
899 	unsigned allow_other:1;
900 
901 	/** Does the filesystem support copy_file_range? */
902 	unsigned no_copy_file_range:1;
903 
904 	/* Send DESTROY request */
905 	unsigned int destroy:1;
906 
907 	/* Delete dentries that have gone stale */
908 	unsigned int delete_stale:1;
909 
910 	/** Do not create entry in fusectl fs */
911 	unsigned int no_control:1;
912 
913 	/** Do not allow MNT_FORCE umount */
914 	unsigned int no_force_umount:1;
915 
916 	/* Auto-mount submounts announced by the server */
917 	unsigned int auto_submounts:1;
918 
919 	/* Propagate syncfs() to server */
920 	unsigned int sync_fs:1;
921 
922 	/* Initialize security xattrs when creating a new inode */
923 	unsigned int init_security:1;
924 
925 	/* Add supplementary group info when creating a new inode */
926 	unsigned int create_supp_group:1;
927 
928 	/* Does the filesystem support per inode DAX? */
929 	unsigned int inode_dax:1;
930 
931 	/* Is tmpfile not implemented by fs? */
932 	unsigned int no_tmpfile:1;
933 
934 	/* Relax restrictions to allow shared mmap in FOPEN_DIRECT_IO mode */
935 	unsigned int direct_io_allow_mmap:1;
936 
937 	/* Is statx not implemented by fs? */
938 	unsigned int no_statx:1;
939 
940 	/** Passthrough support for read/write IO */
941 	unsigned int passthrough:1;
942 
943 	/* Use pages instead of pointer for kernel I/O */
944 	unsigned int use_pages_for_kvec_io:1;
945 
946 	/** BPF Only, no Daemon running */
947 	unsigned int no_daemon:1;
948 
949 	/** Maximum stack depth for passthrough backing files */
950 	int max_stack_depth;
951 
952 	/** The number of requests waiting for completion */
953 	atomic_t num_waiting;
954 
955 	/** Negotiated minor version */
956 	unsigned minor;
957 
958 	/** Entry on the fuse_conn_list */
959 	struct list_head entry;
960 
961 	/** Device ID from the root super block */
962 	dev_t dev;
963 
964 	/** Dentries in the control filesystem */
965 	struct dentry *ctl_dentry[FUSE_CTL_NUM_DENTRIES];
966 
967 	/** number of dentries used in the above array */
968 	int ctl_ndents;
969 
970 	/** Key for lock owner ID scrambling */
971 	u32 scramble_key[4];
972 
973 	/** Version counter for attribute changes */
974 	atomic64_t attr_version;
975 
976 	/** Called on final put */
977 	void (*release)(struct fuse_conn *);
978 
979 	/**
980 	 * Read/write semaphore to hold when accessing the sb of any
981 	 * fuse_mount belonging to this connection
982 	 */
983 	struct rw_semaphore killsb;
984 
985 	/** List of device instances belonging to this connection */
986 	struct list_head devices;
987 
988 #ifdef CONFIG_FUSE_DAX
989 	/* Dax mode */
990 	enum fuse_dax_mode dax_mode;
991 
992 	/* Dax specific conn data, non-NULL if DAX is enabled */
993 	struct fuse_conn_dax *dax;
994 #endif
995 
996 	/** List of filesystems using this connection */
997 	struct list_head mounts;
998 
999 	/* New writepages go into this bucket */
1000 	struct fuse_sync_bucket __rcu *curr_bucket;
1001 
1002 #ifdef CONFIG_FUSE_PASSTHROUGH
1003 	/** IDR for backing files ids */
1004 	struct idr backing_files_map;
1005 #endif
1006 };
1007 
1008 /*
1009  * Represents a mounted filesystem, potentially a submount.
1010  *
1011  * This object allows sharing a fuse_conn between separate mounts to
1012  * allow submounts with dedicated superblocks and thus separate device
1013  * IDs.
1014  */
1015 struct fuse_mount {
1016 	/* Underlying (potentially shared) connection to the FUSE server */
1017 	struct fuse_conn *fc;
1018 
1019 	/*
1020 	 * Super block for this connection (fc->killsb must be held when
1021 	 * accessing this).
1022 	 */
1023 	struct super_block *sb;
1024 
1025 	/* Entry on fc->mounts */
1026 	struct list_head fc_entry;
1027 	struct rcu_head rcu;
1028 };
1029 
get_fuse_mount_super(struct super_block * sb)1030 static inline struct fuse_mount *get_fuse_mount_super(struct super_block *sb)
1031 {
1032 	return sb->s_fs_info;
1033 }
1034 
get_fuse_conn_super(struct super_block * sb)1035 static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
1036 {
1037 	return get_fuse_mount_super(sb)->fc;
1038 }
1039 
get_fuse_mount(struct inode * inode)1040 static inline struct fuse_mount *get_fuse_mount(struct inode *inode)
1041 {
1042 	return get_fuse_mount_super(inode->i_sb);
1043 }
1044 
get_fuse_conn(struct inode * inode)1045 static inline struct fuse_conn *get_fuse_conn(struct inode *inode)
1046 {
1047 	return get_fuse_mount_super(inode->i_sb)->fc;
1048 }
1049 
get_fuse_inode(struct inode * inode)1050 static inline struct fuse_inode *get_fuse_inode(struct inode *inode)
1051 {
1052 	return container_of(inode, struct fuse_inode, inode);
1053 }
1054 
get_node_id(struct inode * inode)1055 static inline u64 get_node_id(struct inode *inode)
1056 {
1057 	return get_fuse_inode(inode)->nodeid;
1058 }
1059 
invalid_nodeid(u64 nodeid)1060 static inline int invalid_nodeid(u64 nodeid)
1061 {
1062 	return !nodeid || nodeid == FUSE_ROOT_ID;
1063 }
1064 
fuse_get_attr_version(struct fuse_conn * fc)1065 static inline u64 fuse_get_attr_version(struct fuse_conn *fc)
1066 {
1067 	return atomic64_read(&fc->attr_version);
1068 }
1069 
fuse_stale_inode(const struct inode * inode,int generation,struct fuse_attr * attr)1070 static inline bool fuse_stale_inode(const struct inode *inode, int generation,
1071 				    struct fuse_attr *attr)
1072 {
1073 	return inode->i_generation != generation ||
1074 		inode_wrong_type(inode, attr->mode);
1075 }
1076 
fuse_make_bad(struct inode * inode)1077 static inline void fuse_make_bad(struct inode *inode)
1078 {
1079 	set_bit(FUSE_I_BAD, &get_fuse_inode(inode)->state);
1080 }
1081 
fuse_is_bad(struct inode * inode)1082 static inline bool fuse_is_bad(struct inode *inode)
1083 {
1084 	return unlikely(test_bit(FUSE_I_BAD, &get_fuse_inode(inode)->state));
1085 }
1086 
fuse_pages_alloc(unsigned int npages,gfp_t flags,struct fuse_page_desc ** desc)1087 static inline struct page **fuse_pages_alloc(unsigned int npages, gfp_t flags,
1088 					     struct fuse_page_desc **desc)
1089 {
1090 	struct page **pages;
1091 
1092 	pages = kzalloc(npages * (sizeof(struct page *) +
1093 				  sizeof(struct fuse_page_desc)), flags);
1094 	*desc = (void *) (pages + npages);
1095 
1096 	return pages;
1097 }
1098 
fuse_page_descs_length_init(struct fuse_page_desc * descs,unsigned int index,unsigned int nr_pages)1099 static inline void fuse_page_descs_length_init(struct fuse_page_desc *descs,
1100 					       unsigned int index,
1101 					       unsigned int nr_pages)
1102 {
1103 	int i;
1104 
1105 	for (i = index; i < index + nr_pages; i++)
1106 		descs[i].length = PAGE_SIZE - descs[i].offset;
1107 }
1108 
fuse_sync_bucket_dec(struct fuse_sync_bucket * bucket)1109 static inline void fuse_sync_bucket_dec(struct fuse_sync_bucket *bucket)
1110 {
1111 	/* Need RCU protection to prevent use after free after the decrement */
1112 	rcu_read_lock();
1113 	if (atomic_dec_and_test(&bucket->count))
1114 		wake_up(&bucket->waitq);
1115 	rcu_read_unlock();
1116 }
1117 
1118 /** Device operations */
1119 extern const struct file_operations fuse_dev_operations;
1120 
1121 extern const struct dentry_operations fuse_dentry_operations;
1122 extern const struct dentry_operations fuse_root_dentry_operations;
1123 
1124 /**
1125  * Get a filled-in inode
1126  */
1127 struct inode *fuse_iget_backing(struct super_block *sb,
1128 				u64 nodeid,
1129 				struct inode *backing_inode);
1130 struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
1131 			int generation, struct fuse_attr *attr,
1132 			u64 attr_valid, u64 attr_version);
1133 
1134 int fuse_lookup_name(struct super_block *sb, u64 nodeid, const struct qstr *name,
1135 		     struct fuse_entry_out *outarg,
1136 		     struct dentry *entry, struct inode **inode);
1137 
1138 /**
1139  * Send FORGET command
1140  */
1141 void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget,
1142 		       u64 nodeid, u64 nlookup);
1143 
1144 struct fuse_forget_link *fuse_alloc_forget(void);
1145 
1146 /*
1147  * Initialize READ or READDIR request
1148  */
1149 struct fuse_io_args {
1150 	union {
1151 		struct {
1152 			struct fuse_read_in in;
1153 			u64 attr_ver;
1154 		} read;
1155 		struct {
1156 			struct fuse_write_in in;
1157 			struct fuse_write_out out;
1158 			bool page_locked;
1159 		} write;
1160 	};
1161 	struct fuse_args_pages ap;
1162 	struct fuse_io_priv *io;
1163 	struct fuse_file *ff;
1164 };
1165 
1166 void fuse_read_args_fill(struct fuse_io_args *ia, struct file *file, loff_t pos,
1167 			 size_t count, int opcode);
1168 
1169 struct fuse_file *fuse_file_alloc(struct fuse_mount *fm, bool release);
1170 void fuse_file_free(struct fuse_file *ff);
1171 int fuse_finish_open(struct inode *inode, struct file *file);
1172 
1173 void fuse_sync_release(struct fuse_inode *fi, struct fuse_file *ff,
1174 		       unsigned int flags);
1175 
1176 /**
1177  * Send RELEASE or RELEASEDIR request
1178  */
1179 void fuse_release_common(struct file *file, bool isdir);
1180 
1181 /**
1182  * Send FSYNC or FSYNCDIR request
1183  */
1184 int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
1185 		      int datasync, int opcode);
1186 
1187 /**
1188  * Notify poll wakeup
1189  */
1190 int fuse_notify_poll_wakeup(struct fuse_conn *fc,
1191 			    struct fuse_notify_poll_wakeup_out *outarg);
1192 
1193 /**
1194  * Initialize file operations on a regular file
1195  */
1196 void fuse_init_file_inode(struct inode *inode, unsigned int flags);
1197 
1198 /**
1199  * Initialize inode operations on regular files and special files
1200  */
1201 void fuse_init_common(struct inode *inode);
1202 
1203 /**
1204  * Initialize inode and file operations on a directory
1205  */
1206 void fuse_init_dir(struct inode *inode);
1207 
1208 /**
1209  * Initialize inode operations on a symlink
1210  */
1211 void fuse_init_symlink(struct inode *inode);
1212 
1213 /**
1214  * Change attributes of an inode
1215  */
1216 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
1217 			    struct fuse_statx *sx,
1218 			    u64 attr_valid, u64 attr_version);
1219 
1220 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
1221 				   struct fuse_statx *sx,
1222 				   u64 attr_valid, u32 cache_mask);
1223 
1224 u32 fuse_get_cache_mask(struct inode *inode);
1225 
1226 /**
1227  * Initialize the client device
1228  */
1229 int fuse_dev_init(void);
1230 
1231 /**
1232  * Cleanup the client device
1233  */
1234 void fuse_dev_cleanup(void);
1235 
1236 int fuse_ctl_init(void);
1237 void fuse_ctl_cleanup(void);
1238 
1239 /**
1240  * Simple request sending that does request allocation and freeing
1241  */
1242 ssize_t __fuse_simple_request(struct mnt_idmap *idmap,
1243 			      struct fuse_mount *fm,
1244 			      struct fuse_args *args);
1245 
fuse_simple_request(struct fuse_mount * fm,struct fuse_args * args)1246 static inline ssize_t fuse_simple_request(struct fuse_mount *fm, struct fuse_args *args)
1247 {
1248 	return __fuse_simple_request(&invalid_mnt_idmap, fm, args);
1249 }
1250 
fuse_simple_idmap_request(struct mnt_idmap * idmap,struct fuse_mount * fm,struct fuse_args * args)1251 static inline ssize_t fuse_simple_idmap_request(struct mnt_idmap *idmap,
1252 						struct fuse_mount *fm,
1253 						struct fuse_args *args)
1254 {
1255 	return __fuse_simple_request(idmap, fm, args);
1256 }
1257 
1258 int fuse_simple_background(struct fuse_mount *fm, struct fuse_args *args,
1259 			   gfp_t gfp_flags);
1260 
1261 /**
1262  * End a finished request
1263  */
1264 void fuse_request_end(struct fuse_req *req);
1265 
1266 /* Abort all requests */
1267 void fuse_abort_conn(struct fuse_conn *fc);
1268 void fuse_wait_aborted(struct fuse_conn *fc);
1269 
1270 /**
1271  * Invalidate inode attributes
1272  */
1273 
1274 /* Attributes possibly changed on data modification */
1275 #define FUSE_STATX_MODIFY	(STATX_MTIME | STATX_CTIME | STATX_BLOCKS)
1276 
1277 /* Attributes possibly changed on data and/or size modification */
1278 #define FUSE_STATX_MODSIZE	(FUSE_STATX_MODIFY | STATX_SIZE)
1279 
1280 void fuse_invalidate_attr(struct inode *inode);
1281 void fuse_invalidate_attr_mask(struct inode *inode, u32 mask);
1282 
1283 void fuse_invalidate_entry_cache(struct dentry *entry);
1284 
1285 void fuse_invalidate_atime(struct inode *inode);
1286 
1287 static u64 fuse_time_to_jiffies(u64 sec, u32 nsec);
1288 #define ATTR_TIMEOUT(o) \
1289 	fuse_time_to_jiffies((o)->attr_valid, (o)->attr_valid_nsec)
1290 
1291 
1292 u64 entry_attr_timeout(struct fuse_entry_out *o);
1293 void fuse_init_dentry_root(struct dentry *root, struct file *backing_dir);
1294 
1295 void fuse_change_entry_timeout(struct dentry *entry, struct fuse_entry_out *o);
1296 
1297 /**
1298  * Acquire reference to fuse_conn
1299  */
1300 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc);
1301 
1302 /**
1303  * Initialize fuse_conn
1304  */
1305 void fuse_conn_init(struct fuse_conn *fc, struct fuse_mount *fm,
1306 		    struct user_namespace *user_ns,
1307 		    const struct fuse_iqueue_ops *fiq_ops, void *fiq_priv);
1308 
1309 /**
1310  * Release reference to fuse_conn
1311  */
1312 void fuse_conn_put(struct fuse_conn *fc);
1313 
1314 struct fuse_dev *fuse_dev_alloc_install(struct fuse_conn *fc);
1315 struct fuse_dev *fuse_dev_alloc(void);
1316 void fuse_dev_install(struct fuse_dev *fud, struct fuse_conn *fc);
1317 void fuse_dev_free(struct fuse_dev *fud);
1318 void fuse_send_init(struct fuse_mount *fm);
1319 
1320 /**
1321  * Fill in superblock and initialize fuse connection
1322  * @sb: partially-initialized superblock to fill in
1323  * @ctx: mount context
1324  */
1325 int fuse_fill_super_common(struct super_block *sb, struct fuse_fs_context *ctx);
1326 
1327 /*
1328  * Remove the mount from the connection
1329  *
1330  * Returns whether this was the last mount
1331  */
1332 bool fuse_mount_remove(struct fuse_mount *fm);
1333 
1334 /*
1335  * Setup context ops for submounts
1336  */
1337 int fuse_init_fs_context_submount(struct fs_context *fsc);
1338 
1339 /*
1340  * Shut down the connection (possibly sending DESTROY request).
1341  */
1342 void fuse_conn_destroy(struct fuse_mount *fm);
1343 
1344 /* Drop the connection and free the fuse mount */
1345 void fuse_mount_destroy(struct fuse_mount *fm);
1346 
1347 /**
1348  * Add connection to control filesystem
1349  */
1350 int fuse_ctl_add_conn(struct fuse_conn *fc);
1351 
1352 /**
1353  * Remove connection from control filesystem
1354  */
1355 void fuse_ctl_remove_conn(struct fuse_conn *fc);
1356 
1357 /**
1358  * Is file type valid?
1359  */
1360 int fuse_valid_type(int m);
1361 
1362 bool fuse_invalid_attr(struct fuse_attr *attr);
1363 
1364 /**
1365  * Is current process allowed to perform filesystem operation?
1366  */
1367 bool fuse_allow_current_process(struct fuse_conn *fc);
1368 
1369 u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id);
1370 
1371 void fuse_flush_time_update(struct inode *inode);
1372 void fuse_update_ctime(struct inode *inode);
1373 
1374 int fuse_update_attributes(struct inode *inode, struct file *file, u32 mask);
1375 
1376 void fuse_flush_writepages(struct inode *inode);
1377 
1378 void fuse_set_nowrite(struct inode *inode);
1379 void fuse_release_nowrite(struct inode *inode);
1380 
1381 /**
1382  * Scan all fuse_mounts belonging to fc to find the first where
1383  * ilookup5() returns a result.  Return that result and the
1384  * respective fuse_mount in *fm (unless fm is NULL).
1385  *
1386  * The caller must hold fc->killsb.
1387  */
1388 struct inode *fuse_ilookup(struct fuse_conn *fc, u64 nodeid,
1389 			   struct fuse_mount **fm);
1390 
1391 /**
1392  * File-system tells the kernel to invalidate cache for the given node id.
1393  */
1394 int fuse_reverse_inval_inode(struct fuse_conn *fc, u64 nodeid,
1395 			     loff_t offset, loff_t len);
1396 
1397 /**
1398  * File-system tells the kernel to invalidate parent attributes and
1399  * the dentry matching parent/name.
1400  *
1401  * If the child_nodeid is non-zero and:
1402  *    - matches the inode number for the dentry matching parent/name,
1403  *    - is not a mount point
1404  *    - is a file or oan empty directory
1405  * then the dentry is unhashed (d_delete()).
1406  */
1407 int fuse_reverse_inval_entry(struct fuse_conn *fc, u64 parent_nodeid,
1408 			     u64 child_nodeid, struct qstr *name, u32 flags);
1409 
1410 int fuse_do_open(struct fuse_mount *fm, u64 nodeid, struct file *file,
1411 		 bool isdir);
1412 
1413 /**
1414  * fuse_direct_io() flags
1415  */
1416 
1417 /** If set, it is WRITE; otherwise - READ */
1418 #define FUSE_DIO_WRITE (1 << 0)
1419 
1420 /** CUSE pass fuse_direct_io() a file which f_mapping->host is not from FUSE */
1421 #define FUSE_DIO_CUSE  (1 << 1)
1422 
1423 ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter,
1424 		       loff_t *ppos, int flags);
1425 long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
1426 		   unsigned int flags);
1427 long fuse_ioctl_common(struct file *file, unsigned int cmd,
1428 		       unsigned long arg, unsigned int flags);
1429 __poll_t fuse_file_poll(struct file *file, poll_table *wait);
1430 int fuse_dev_release(struct inode *inode, struct file *file);
1431 
1432 bool fuse_write_update_attr(struct inode *inode, loff_t pos, ssize_t written);
1433 
1434 int fuse_flush_times(struct inode *inode, struct fuse_file *ff);
1435 int fuse_write_inode(struct inode *inode, struct writeback_control *wbc);
1436 
1437 int fuse_do_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
1438 		    struct iattr *attr, struct file *file);
1439 
1440 void fuse_set_initialized(struct fuse_conn *fc);
1441 
1442 void fuse_unlock_inode(struct inode *inode, bool locked);
1443 bool fuse_lock_inode(struct inode *inode);
1444 
1445 int fuse_setxattr(struct inode *inode, const char *name, const void *value,
1446 		  size_t size, int flags, unsigned int extra_flags);
1447 ssize_t fuse_getxattr(struct inode *inode, const char *name, void *value,
1448 		      size_t size);
1449 ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size);
1450 int fuse_removexattr(struct inode *inode, const char *name);
1451 extern const struct xattr_handler * const fuse_xattr_handlers[];
1452 
1453 struct posix_acl;
1454 struct posix_acl *fuse_get_inode_acl(struct inode *inode, int type, bool rcu);
1455 struct posix_acl *fuse_get_acl(struct mnt_idmap *idmap,
1456 			       struct dentry *dentry, int type);
1457 int fuse_set_acl(struct mnt_idmap *, struct dentry *dentry,
1458 		 struct posix_acl *acl, int type);
1459 
1460 /* readdir.c */
1461 int fuse_readdir(struct file *file, struct dir_context *ctx);
1462 
1463 /**
1464  * Return the number of bytes in an arguments list
1465  */
1466 unsigned int fuse_len_args(unsigned int numargs, struct fuse_arg *args);
1467 
1468 /**
1469  * Get the next unique ID for a request
1470  */
1471 u64 fuse_get_unique(struct fuse_iqueue *fiq);
1472 void fuse_free_conn(struct fuse_conn *fc);
1473 
1474 /* dax.c */
1475 
1476 #define FUSE_IS_DAX(inode) (IS_ENABLED(CONFIG_FUSE_DAX) && IS_DAX(inode))
1477 
1478 ssize_t fuse_dax_read_iter(struct kiocb *iocb, struct iov_iter *to);
1479 ssize_t fuse_dax_write_iter(struct kiocb *iocb, struct iov_iter *from);
1480 int fuse_dax_mmap(struct file *file, struct vm_area_struct *vma);
1481 int fuse_dax_break_layouts(struct inode *inode, u64 dmap_start, u64 dmap_end);
1482 int fuse_dax_conn_alloc(struct fuse_conn *fc, enum fuse_dax_mode mode,
1483 			struct dax_device *dax_dev);
1484 void fuse_dax_conn_free(struct fuse_conn *fc);
1485 bool fuse_dax_inode_alloc(struct super_block *sb, struct fuse_inode *fi);
1486 void fuse_dax_inode_init(struct inode *inode, unsigned int flags);
1487 void fuse_dax_inode_cleanup(struct inode *inode);
1488 void fuse_dax_dontcache(struct inode *inode, unsigned int flags);
1489 bool fuse_dax_check_alignment(struct fuse_conn *fc, unsigned int map_alignment);
1490 void fuse_dax_cancel_work(struct fuse_conn *fc);
1491 
1492 /* ioctl.c */
1493 long fuse_file_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
1494 long fuse_file_compat_ioctl(struct file *file, unsigned int cmd,
1495 			    unsigned long arg);
1496 int fuse_fileattr_get(struct dentry *dentry, struct fileattr *fa);
1497 int fuse_fileattr_set(struct mnt_idmap *idmap,
1498 		      struct dentry *dentry, struct fileattr *fa);
1499 
1500 /* iomode.c */
1501 int fuse_file_cached_io_open(struct inode *inode, struct fuse_file *ff);
1502 int fuse_inode_uncached_io_start(struct fuse_inode *fi,
1503 				 struct fuse_backing *fb);
1504 void fuse_inode_uncached_io_end(struct fuse_inode *fi);
1505 
1506 int fuse_file_io_open(struct file *file, struct inode *inode);
1507 void fuse_file_io_release(struct fuse_file *ff, struct inode *inode);
1508 
1509 /* file.c */
1510 struct fuse_file *fuse_file_open(struct fuse_mount *fm, u64 nodeid,
1511 				 unsigned int open_flags, bool isdir);
1512 void fuse_file_release(struct inode *inode, struct fuse_file *ff,
1513 		       unsigned int open_flags, fl_owner_t id, bool isdir);
1514 
1515 /* passthrough.c */
fuse_inode_backing(struct fuse_inode * fi)1516 static inline struct fuse_backing *fuse_inode_backing(struct fuse_inode *fi)
1517 {
1518 #ifdef CONFIG_FUSE_PASSTHROUGH
1519 	return READ_ONCE(fi->fb);
1520 #else
1521 	return NULL;
1522 #endif
1523 }
1524 
fuse_inode_backing_set(struct fuse_inode * fi,struct fuse_backing * fb)1525 static inline struct fuse_backing *fuse_inode_backing_set(struct fuse_inode *fi,
1526 							  struct fuse_backing *fb)
1527 {
1528 #ifdef CONFIG_FUSE_PASSTHROUGH
1529 	return xchg(&fi->fb, fb);
1530 #else
1531 	return NULL;
1532 #endif
1533 }
1534 
1535 #ifdef CONFIG_FUSE_PASSTHROUGH
1536 struct fuse_backing *fuse_backing_get(struct fuse_backing *fb);
1537 void fuse_backing_put(struct fuse_backing *fb);
1538 #else
1539 
fuse_backing_get(struct fuse_backing * fb)1540 static inline struct fuse_backing *fuse_backing_get(struct fuse_backing *fb)
1541 {
1542 	return NULL;
1543 }
1544 
fuse_backing_put(struct fuse_backing * fb)1545 static inline void fuse_backing_put(struct fuse_backing *fb)
1546 {
1547 }
1548 #endif
1549 
1550 void fuse_backing_files_init(struct fuse_conn *fc);
1551 void fuse_backing_files_free(struct fuse_conn *fc);
1552 int fuse_backing_open(struct fuse_conn *fc, struct fuse_backing_map *map);
1553 int fuse_backing_close(struct fuse_conn *fc, int backing_id);
1554 
1555 struct fuse_backing *fuse_passthrough_open(struct file *file,
1556 					   struct inode *inode,
1557 					   int backing_id);
1558 void fuse_passthrough_release(struct fuse_file *ff, struct fuse_backing *fb);
1559 
fuse_file_passthrough(struct fuse_file * ff)1560 static inline struct file *fuse_file_passthrough(struct fuse_file *ff)
1561 {
1562 #ifdef CONFIG_FUSE_PASSTHROUGH
1563 	return ff->passthrough;
1564 #else
1565 	return NULL;
1566 #endif
1567 }
1568 
1569 ssize_t fuse_passthrough_read_iter(struct kiocb *iocb, struct iov_iter *iter);
1570 ssize_t fuse_passthrough_write_iter(struct kiocb *iocb, struct iov_iter *iter);
1571 ssize_t fuse_passthrough_splice_read(struct file *in, loff_t *ppos,
1572 				     struct pipe_inode_info *pipe,
1573 				     size_t len, unsigned int flags);
1574 ssize_t fuse_passthrough_splice_write(struct pipe_inode_info *pipe,
1575 				      struct file *out, loff_t *ppos,
1576 				      size_t len, unsigned int flags);
1577 ssize_t fuse_passthrough_mmap(struct file *file, struct vm_area_struct *vma);
1578 
1579 /* backing.c */
1580 
1581 /*
1582  * Dummy io passed to fuse_bpf_backing when io operation needs no scratch space
1583  */
1584 struct fuse_dummy_io {
1585 	int unused;
1586 };
1587 
1588 struct fuse_open_io {
1589 	struct fuse_open_in foi;
1590 	struct fuse_open_out foo;
1591 };
1592 
1593 int fuse_open_initialize(struct fuse_bpf_args *fa, struct fuse_open_io *foi,
1594 			 struct inode *inode, struct file *file, bool isdir);
1595 int fuse_open_backing(struct fuse_bpf_args *fa,
1596 		      struct inode *inode, struct file *file, bool isdir);
1597 void *fuse_open_finalize(struct fuse_bpf_args *fa,
1598 		       struct inode *inode, struct file *file, bool isdir);
1599 
1600 struct fuse_create_open_io {
1601 	struct fuse_create_in fci;
1602 	struct fuse_entry_out feo;
1603 	struct fuse_open_out foo;
1604 };
1605 
1606 int fuse_create_open_initialize(
1607 		struct fuse_bpf_args *fa, struct fuse_create_open_io *fcoi,
1608 		struct inode *dir, struct dentry *entry,
1609 		struct file *file, unsigned int flags, umode_t mode);
1610 int fuse_create_open_backing(
1611 		struct fuse_bpf_args *fa,
1612 		struct inode *dir, struct dentry *entry,
1613 		struct file *file, unsigned int flags, umode_t mode);
1614 void *fuse_create_open_finalize(
1615 		struct fuse_bpf_args *fa,
1616 		struct inode *dir, struct dentry *entry,
1617 		struct file *file, unsigned int flags, umode_t mode);
1618 
1619 int fuse_mknod_initialize(
1620 		struct fuse_bpf_args *fa, struct fuse_mknod_in *fmi,
1621 		struct inode *dir, struct dentry *entry, umode_t mode, dev_t rdev);
1622 int fuse_mknod_backing(
1623 		struct fuse_bpf_args *fa,
1624 		struct inode *dir, struct dentry *entry, umode_t mode, dev_t rdev);
1625 void *fuse_mknod_finalize(
1626 		struct fuse_bpf_args *fa,
1627 		struct inode *dir, struct dentry *entry, umode_t mode, dev_t rdev);
1628 
1629 int fuse_mkdir_initialize(
1630 		struct fuse_bpf_args *fa, struct fuse_mkdir_in *fmi,
1631 		struct inode *dir, struct dentry *entry, umode_t mode);
1632 int fuse_mkdir_backing(
1633 		struct fuse_bpf_args *fa,
1634 		struct inode *dir, struct dentry *entry, umode_t mode);
1635 void *fuse_mkdir_finalize(
1636 		struct fuse_bpf_args *fa,
1637 		struct inode *dir, struct dentry *entry, umode_t mode);
1638 
1639 int fuse_rmdir_initialize(
1640 		struct fuse_bpf_args *fa, struct fuse_dummy_io *fmi,
1641 		struct inode *dir, struct dentry *entry);
1642 int fuse_rmdir_backing(
1643 		struct fuse_bpf_args *fa,
1644 		struct inode *dir, struct dentry *entry);
1645 void *fuse_rmdir_finalize(
1646 		struct fuse_bpf_args *fa,
1647 		struct inode *dir, struct dentry *entry);
1648 
1649 int fuse_rename2_initialize(struct fuse_bpf_args *fa, struct fuse_rename2_in *fri,
1650 			    struct inode *olddir, struct dentry *oldent,
1651 			    struct inode *newdir, struct dentry *newent,
1652 			    unsigned int flags);
1653 int fuse_rename2_backing(struct fuse_bpf_args *fa,
1654 			 struct inode *olddir, struct dentry *oldent,
1655 			 struct inode *newdir, struct dentry *newent,
1656 			 unsigned int flags);
1657 void *fuse_rename2_finalize(struct fuse_bpf_args *fa,
1658 			    struct inode *olddir, struct dentry *oldent,
1659 			    struct inode *newdir, struct dentry *newent,
1660 			    unsigned int flags);
1661 
1662 int fuse_rename_initialize(struct fuse_bpf_args *fa, struct fuse_rename_in *fri,
1663 			   struct inode *olddir, struct dentry *oldent,
1664 			   struct inode *newdir, struct dentry *newent);
1665 int fuse_rename_backing(struct fuse_bpf_args *fa,
1666 			struct inode *olddir, struct dentry *oldent,
1667 			struct inode *newdir, struct dentry *newent);
1668 void *fuse_rename_finalize(struct fuse_bpf_args *fa,
1669 			   struct inode *olddir, struct dentry *oldent,
1670 			   struct inode *newdir, struct dentry *newent);
1671 
1672 int fuse_unlink_initialize(
1673 		struct fuse_bpf_args *fa, struct fuse_dummy_io *fmi,
1674 		struct inode *dir, struct dentry *entry);
1675 int fuse_unlink_backing(
1676 		struct fuse_bpf_args *fa,
1677 		struct inode *dir, struct dentry *entry);
1678 void *fuse_unlink_finalize(
1679 		struct fuse_bpf_args *fa,
1680 		struct inode *dir, struct dentry *entry);
1681 
1682 int fuse_link_initialize(struct fuse_bpf_args *fa, struct fuse_link_in *fli,
1683 			  struct dentry *entry, struct inode *dir,
1684 			  struct dentry *newent);
1685 int fuse_link_backing(struct fuse_bpf_args *fa, struct dentry *entry,
1686 		      struct inode *dir, struct dentry *newent);
1687 void *fuse_link_finalize(struct fuse_bpf_args *fa, struct dentry *entry,
1688 			 struct inode *dir, struct dentry *newent);
1689 
1690 int fuse_release_initialize(struct fuse_bpf_args *fa, struct fuse_release_in *fri,
1691 			    struct inode *inode, struct fuse_file *ff);
1692 int fuse_release_backing(struct fuse_bpf_args *fa,
1693 			 struct inode *inode, struct fuse_file *ff);
1694 void *fuse_release_finalize(struct fuse_bpf_args *fa,
1695 			    struct inode *inode, struct fuse_file *ff);
1696 
1697 int fuse_flush_initialize(struct fuse_bpf_args *fa, struct fuse_flush_in *ffi,
1698 			  struct file *file, fl_owner_t id);
1699 int fuse_flush_backing(struct fuse_bpf_args *fa, struct file *file, fl_owner_t id);
1700 void *fuse_flush_finalize(struct fuse_bpf_args *fa,
1701 			  struct file *file, fl_owner_t id);
1702 
1703 struct fuse_lseek_io {
1704 	struct fuse_lseek_in fli;
1705 	struct fuse_lseek_out flo;
1706 };
1707 
1708 int fuse_lseek_initialize(struct fuse_bpf_args *fa, struct fuse_lseek_io *fli,
1709 			  struct file *file, loff_t offset, int whence);
1710 int fuse_lseek_backing(struct fuse_bpf_args *fa, struct file *file, loff_t offset, int whence);
1711 void *fuse_lseek_finalize(struct fuse_bpf_args *fa, struct file *file, loff_t offset, int whence);
1712 
1713 struct fuse_copy_file_range_io {
1714 	struct fuse_copy_file_range_in fci;
1715 	struct fuse_write_out fwo;
1716 };
1717 
1718 int fuse_copy_file_range_initialize(struct fuse_bpf_args *fa,
1719 				   struct fuse_copy_file_range_io *fcf,
1720 				   struct file *file_in, loff_t pos_in,
1721 				   struct file *file_out, loff_t pos_out,
1722 				   size_t len, unsigned int flags);
1723 int fuse_copy_file_range_backing(struct fuse_bpf_args *fa,
1724 				 struct file *file_in, loff_t pos_in,
1725 				 struct file *file_out, loff_t pos_out,
1726 				 size_t len, unsigned int flags);
1727 void *fuse_copy_file_range_finalize(struct fuse_bpf_args *fa,
1728 				    struct file *file_in, loff_t pos_in,
1729 				    struct file *file_out, loff_t pos_out,
1730 				    size_t len, unsigned int flags);
1731 
1732 int fuse_fsync_initialize(struct fuse_bpf_args *fa, struct fuse_fsync_in *ffi,
1733 		   struct file *file, loff_t start, loff_t end, int datasync);
1734 int fuse_fsync_backing(struct fuse_bpf_args *fa,
1735 		   struct file *file, loff_t start, loff_t end, int datasync);
1736 void *fuse_fsync_finalize(struct fuse_bpf_args *fa,
1737 		   struct file *file, loff_t start, loff_t end, int datasync);
1738 int fuse_dir_fsync_initialize(struct fuse_bpf_args *fa, struct fuse_fsync_in *ffi,
1739 		   struct file *file, loff_t start, loff_t end, int datasync);
1740 
1741 struct fuse_getxattr_io {
1742 	struct fuse_getxattr_in fgi;
1743 	struct fuse_getxattr_out fgo;
1744 };
1745 
1746 int fuse_getxattr_initialize(
1747 		struct fuse_bpf_args *fa, struct fuse_getxattr_io *fgio,
1748 		struct dentry *dentry, const char *name, void *value,
1749 		size_t size);
1750 int fuse_getxattr_backing(
1751 		struct fuse_bpf_args *fa,
1752 		struct dentry *dentry, const char *name, void *value,
1753 		size_t size);
1754 void *fuse_getxattr_finalize(
1755 		struct fuse_bpf_args *fa,
1756 		struct dentry *dentry, const char *name, void *value,
1757 		size_t size);
1758 
1759 int fuse_listxattr_initialize(struct fuse_bpf_args *fa,
1760 			       struct fuse_getxattr_io *fgio,
1761 			       struct dentry *dentry, char *list, size_t size);
1762 int fuse_listxattr_backing(struct fuse_bpf_args *fa, struct dentry *dentry,
1763 			   char *list, size_t size);
1764 void *fuse_listxattr_finalize(struct fuse_bpf_args *fa, struct dentry *dentry,
1765 			      char *list, size_t size);
1766 
1767 int fuse_setxattr_initialize(struct fuse_bpf_args *fa,
1768 			     struct fuse_setxattr_in *fsxi,
1769 			     struct dentry *dentry, const char *name,
1770 			     const void *value, size_t size, int flags);
1771 int fuse_setxattr_backing(struct fuse_bpf_args *fa, struct dentry *dentry,
1772 			  const char *name, const void *value, size_t size,
1773 			  int flags);
1774 void *fuse_setxattr_finalize(struct fuse_bpf_args *fa, struct dentry *dentry,
1775 			     const char *name, const void *value, size_t size,
1776 			     int flags);
1777 
1778 int fuse_removexattr_initialize(struct fuse_bpf_args *fa,
1779 				struct fuse_dummy_io *unused,
1780 				struct dentry *dentry, const char *name);
1781 int fuse_removexattr_backing(struct fuse_bpf_args *fa,
1782 			     struct dentry *dentry, const char *name);
1783 void *fuse_removexattr_finalize(struct fuse_bpf_args *fa,
1784 				struct dentry *dentry, const char *name);
1785 
1786 struct fuse_read_iter_out {
1787 	uint64_t ret;
1788 };
1789 struct fuse_file_read_iter_io {
1790 	struct fuse_read_in fri;
1791 	struct fuse_read_iter_out frio;
1792 };
1793 
1794 int fuse_file_read_iter_initialize(
1795 		struct fuse_bpf_args *fa, struct fuse_file_read_iter_io *fri,
1796 		struct kiocb *iocb, struct iov_iter *to);
1797 int fuse_file_read_iter_backing(struct fuse_bpf_args *fa,
1798 		struct kiocb *iocb, struct iov_iter *to);
1799 void *fuse_file_read_iter_finalize(struct fuse_bpf_args *fa,
1800 		struct kiocb *iocb, struct iov_iter *to);
1801 
1802 struct fuse_write_iter_out {
1803 	uint64_t ret;
1804 };
1805 struct fuse_file_write_iter_io {
1806 	struct fuse_write_in fwi;
1807 	struct fuse_write_out fwo;
1808 	struct fuse_write_iter_out fwio;
1809 };
1810 
1811 int fuse_file_write_iter_initialize(
1812 		struct fuse_bpf_args *fa, struct fuse_file_write_iter_io *fwio,
1813 		struct kiocb *iocb, struct iov_iter *from);
1814 int fuse_file_write_iter_backing(struct fuse_bpf_args *fa,
1815 		struct kiocb *iocb, struct iov_iter *from);
1816 void *fuse_file_write_iter_finalize(struct fuse_bpf_args *fa,
1817 		struct kiocb *iocb, struct iov_iter *from);
1818 
1819 ssize_t fuse_splice_read_backing(struct file *in, loff_t *ppos,
1820 		struct pipe_inode_info *pipe, size_t len, unsigned long flags);
1821 ssize_t fuse_splice_write_backing(struct pipe_inode_info *pipe,
1822 		struct file *out, loff_t *ppos, size_t len, unsigned long flags);
1823 
1824 long fuse_backing_ioctl(struct file *file, unsigned int command, unsigned long arg, int flags);
1825 
1826 int fuse_file_flock_backing(struct file *file, int cmd, struct file_lock *fl);
1827 ssize_t fuse_backing_mmap(struct file *file, struct vm_area_struct *vma);
1828 
1829 int fuse_file_fallocate_initialize(struct fuse_bpf_args *fa,
1830 		struct fuse_fallocate_in *ffi,
1831 		struct file *file, int mode, loff_t offset, loff_t length);
1832 int fuse_file_fallocate_backing(struct fuse_bpf_args *fa,
1833 		struct file *file, int mode, loff_t offset, loff_t length);
1834 void *fuse_file_fallocate_finalize(struct fuse_bpf_args *fa,
1835 		struct file *file, int mode, loff_t offset, loff_t length);
1836 
1837 struct fuse_lookup_io {
1838 	struct fuse_entry_out feo;
1839 	struct fuse_entry_bpf feb;
1840 };
1841 
1842 int fuse_handle_backing(struct fuse_entry_bpf *feb, struct inode **backing_inode,
1843 			struct path *backing_path);
1844 int fuse_handle_bpf_prog(struct fuse_entry_bpf *feb, struct inode *parent,
1845 			 struct bpf_prog **bpf);
1846 
1847 int fuse_lookup_initialize(struct fuse_bpf_args *fa, struct fuse_lookup_io *feo,
1848 	       struct inode *dir, struct dentry *entry, unsigned int flags);
1849 int fuse_lookup_backing(struct fuse_bpf_args *fa, struct inode *dir,
1850 			  struct dentry *entry, unsigned int flags);
1851 struct dentry *fuse_lookup_finalize(struct fuse_bpf_args *fa, struct inode *dir,
1852 			   struct dentry *entry, unsigned int flags);
1853 int fuse_revalidate_backing(struct dentry *entry, unsigned int flags);
1854 
1855 int fuse_canonical_path_initialize(struct fuse_bpf_args *fa,
1856 				   struct fuse_dummy_io *fdi,
1857 				   const struct path *path,
1858 				   struct path *canonical_path);
1859 int fuse_canonical_path_backing(struct fuse_bpf_args *fa, const struct path *path,
1860 				struct path *canonical_path);
1861 void *fuse_canonical_path_finalize(struct fuse_bpf_args *fa,
1862 				   const struct path *path,
1863 				   struct path *canonical_path);
1864 
1865 struct fuse_getattr_io {
1866 	struct fuse_getattr_in fgi;
1867 	struct fuse_attr_out fao;
1868 };
1869 int fuse_getattr_initialize(struct fuse_bpf_args *fa, struct fuse_getattr_io *fgio,
1870 			const struct dentry *entry, struct kstat *stat,
1871 			u32 request_mask, unsigned int flags);
1872 int fuse_getattr_backing(struct fuse_bpf_args *fa,
1873 			const struct dentry *entry, struct kstat *stat,
1874 			u32 request_mask, unsigned int flags);
1875 void *fuse_getattr_finalize(struct fuse_bpf_args *fa,
1876 			const struct dentry *entry, struct kstat *stat,
1877 			u32 request_mask, unsigned int flags);
1878 
1879 struct fuse_setattr_io {
1880 	struct fuse_setattr_in fsi;
1881 	struct fuse_attr_out fao;
1882 };
1883 
1884 int fuse_setattr_initialize(struct fuse_bpf_args *fa, struct fuse_setattr_io *fsi,
1885 		struct dentry *dentry, struct iattr *attr, struct file *file);
1886 int fuse_setattr_backing(struct fuse_bpf_args *fa,
1887 		struct dentry *dentry, struct iattr *attr, struct file *file);
1888 void *fuse_setattr_finalize(struct fuse_bpf_args *fa,
1889 		struct dentry *dentry, struct iattr *attr, struct file *file);
1890 
1891 int fuse_statfs_initialize(struct fuse_bpf_args *fa, struct fuse_statfs_out *fso,
1892 		struct dentry *dentry, struct kstatfs *buf);
1893 int fuse_statfs_backing(struct fuse_bpf_args *fa,
1894 		struct dentry *dentry, struct kstatfs *buf);
1895 void *fuse_statfs_finalize(struct fuse_bpf_args *fa,
1896 		struct dentry *dentry, struct kstatfs *buf);
1897 
1898 int fuse_get_link_initialize(struct fuse_bpf_args *fa, struct fuse_dummy_io *dummy,
1899 		struct inode *inode, struct dentry *dentry,
1900 		struct delayed_call *callback, const char **out);
1901 int fuse_get_link_backing(struct fuse_bpf_args *fa,
1902 		struct inode *inode, struct dentry *dentry,
1903 		struct delayed_call *callback, const char **out);
1904 void *fuse_get_link_finalize(struct fuse_bpf_args *fa,
1905 		struct inode *inode, struct dentry *dentry,
1906 		struct delayed_call *callback, const char **out);
1907 
1908 int fuse_symlink_initialize(
1909 		struct fuse_bpf_args *fa, struct fuse_dummy_io *unused,
1910 		struct inode *dir, struct dentry *entry, const char *link, int len);
1911 int fuse_symlink_backing(
1912 		struct fuse_bpf_args *fa,
1913 		struct inode *dir, struct dentry *entry, const char *link, int len);
1914 void *fuse_symlink_finalize(
1915 		struct fuse_bpf_args *fa,
1916 		struct inode *dir, struct dentry *entry, const char *link, int len);
1917 
1918 struct fuse_read_io {
1919 	struct fuse_read_in fri;
1920 	struct fuse_read_out fro;
1921 };
1922 
1923 int fuse_readdir_initialize(struct fuse_bpf_args *fa, struct fuse_read_io *frio,
1924 			    struct file *file, struct dir_context *ctx,
1925 			    bool *force_again, bool *allow_force, bool is_continued);
1926 int fuse_readdir_backing(struct fuse_bpf_args *fa,
1927 			 struct file *file, struct dir_context *ctx,
1928 			 bool *force_again, bool *allow_force, bool is_continued);
1929 void *fuse_readdir_finalize(struct fuse_bpf_args *fa,
1930 			    struct file *file, struct dir_context *ctx,
1931 			    bool *force_again, bool *allow_force, bool is_continued);
1932 
1933 int fuse_access_initialize(struct fuse_bpf_args *fa, struct fuse_access_in *fai,
1934 			   struct inode *inode, int mask);
1935 int fuse_access_backing(struct fuse_bpf_args *fa, struct inode *inode, int mask);
1936 void *fuse_access_finalize(struct fuse_bpf_args *fa, struct inode *inode, int mask);
1937 
1938 /*
1939  * FUSE caches dentries and attributes with separate timeout.  The
1940  * time in jiffies until the dentry/attributes are valid is stored in
1941  * dentry->d_fsdata and fuse_inode->i_time respectively.
1942  */
1943 
1944 /*
1945  * Calculate the time in jiffies until a dentry/attributes are valid
1946  */
fuse_time_to_jiffies(u64 sec,u32 nsec)1947 inline u64 fuse_time_to_jiffies(u64 sec, u32 nsec)
1948 {
1949 	if (sec || nsec) {
1950 		struct timespec64 ts = {
1951 			sec,
1952 			min_t(u32, nsec, NSEC_PER_SEC - 1)
1953 		};
1954 
1955 		return get_jiffies_64() + timespec64_to_jiffies(&ts);
1956 	} else
1957 		return 0;
1958 }
1959 
attr_timeout(struct fuse_attr_out * o)1960 static inline u64 attr_timeout(struct fuse_attr_out *o)
1961 {
1962 	return fuse_time_to_jiffies(o->attr_valid, o->attr_valid_nsec);
1963 }
1964 
update_mtime(unsigned int ivalid,bool trust_local_mtime)1965 static inline bool update_mtime(unsigned int ivalid, bool trust_local_mtime)
1966 {
1967 	/* Always update if mtime is explicitly set  */
1968 	if (ivalid & ATTR_MTIME_SET)
1969 		return true;
1970 
1971 	/* Or if kernel i_mtime is the official one */
1972 	if (trust_local_mtime)
1973 		return true;
1974 
1975 	/* If it's an open(O_TRUNC) or an ftruncate(), don't update */
1976 	if ((ivalid & ATTR_SIZE) && (ivalid & (ATTR_OPEN | ATTR_FILE)))
1977 		return false;
1978 
1979 	/* In all other cases update */
1980 	return true;
1981 }
1982 
iattr_to_fattr(struct mnt_idmap * idmap,struct fuse_conn * fc,struct iattr * iattr,struct fuse_setattr_in * arg,bool trust_local_cmtime)1983 static inline void iattr_to_fattr(struct mnt_idmap *idmap, struct fuse_conn *fc,
1984 			   struct iattr *iattr, struct fuse_setattr_in *arg,
1985 			   bool trust_local_cmtime)
1986 {
1987 	unsigned ivalid = iattr->ia_valid;
1988 
1989 	if (ivalid & ATTR_MODE)
1990 		arg->valid |= FATTR_MODE,   arg->mode = iattr->ia_mode;
1991 
1992 	if (ivalid & ATTR_UID) {
1993 		kuid_t fsuid = from_vfsuid(idmap, fc->user_ns, iattr->ia_vfsuid);
1994 
1995 		arg->valid |= FATTR_UID;
1996 		arg->uid = from_kuid(fc->user_ns, fsuid);
1997 	}
1998 
1999 	if (ivalid & ATTR_GID) {
2000 		kgid_t fsgid = from_vfsgid(idmap, fc->user_ns, iattr->ia_vfsgid);
2001 
2002 		arg->valid |= FATTR_GID;
2003 		arg->gid = from_kgid(fc->user_ns, fsgid);
2004 	}
2005 
2006 	if (ivalid & ATTR_SIZE)
2007 		arg->valid |= FATTR_SIZE,   arg->size = iattr->ia_size;
2008 	if (ivalid & ATTR_ATIME) {
2009 		arg->valid |= FATTR_ATIME;
2010 		arg->atime = iattr->ia_atime.tv_sec;
2011 		arg->atimensec = iattr->ia_atime.tv_nsec;
2012 		if (!(ivalid & ATTR_ATIME_SET))
2013 			arg->valid |= FATTR_ATIME_NOW;
2014 	}
2015 	if ((ivalid & ATTR_MTIME) && update_mtime(ivalid, trust_local_cmtime)) {
2016 		arg->valid |= FATTR_MTIME;
2017 		arg->mtime = iattr->ia_mtime.tv_sec;
2018 		arg->mtimensec = iattr->ia_mtime.tv_nsec;
2019 		if (!(ivalid & ATTR_MTIME_SET) && !trust_local_cmtime)
2020 			arg->valid |= FATTR_MTIME_NOW;
2021 	}
2022 	if ((ivalid & ATTR_CTIME) && trust_local_cmtime) {
2023 		arg->valid |= FATTR_CTIME;
2024 		arg->ctime = iattr->ia_ctime.tv_sec;
2025 		arg->ctimensec = iattr->ia_ctime.tv_nsec;
2026 	}
2027 }
2028 
2029 void fuse_fillattr(struct mnt_idmap *idmap, struct inode *inode, struct fuse_attr *attr,
2030 			  struct kstat *stat);
2031 
finalize_attr(struct inode * inode,struct fuse_attr_out * outarg,u64 attr_version,struct kstat * stat)2032 static inline int finalize_attr(struct inode *inode, struct fuse_attr_out *outarg,
2033 				u64 attr_version, struct kstat *stat)
2034 {
2035 	int err = 0;
2036 
2037 	if (fuse_invalid_attr(&outarg->attr) ||
2038 	    inode_wrong_type(inode, outarg->attr.mode)) {
2039 		fuse_make_bad(inode);
2040 		err = -EIO;
2041 	} else {
2042 		fuse_change_attributes(inode, &outarg->attr, NULL,
2043 				       ATTR_TIMEOUT(outarg),
2044 				       attr_version);
2045 		if (stat)
2046 			fuse_fillattr(&nop_mnt_idmap, inode, &outarg->attr, stat);
2047 	}
2048 	return err;
2049 }
2050 
convert_statfs_to_fuse(struct fuse_kstatfs * attr,struct kstatfs * stbuf)2051 static inline void convert_statfs_to_fuse(struct fuse_kstatfs *attr, struct kstatfs *stbuf)
2052 {
2053 	attr->bsize   = stbuf->f_bsize;
2054 	attr->frsize  = stbuf->f_frsize;
2055 	attr->blocks  = stbuf->f_blocks;
2056 	attr->bfree   = stbuf->f_bfree;
2057 	attr->bavail  = stbuf->f_bavail;
2058 	attr->files   = stbuf->f_files;
2059 	attr->ffree   = stbuf->f_ffree;
2060 	attr->namelen = stbuf->f_namelen;
2061 	/* fsid is left zero */
2062 }
2063 
convert_fuse_statfs(struct kstatfs * stbuf,struct fuse_kstatfs * attr)2064 static inline void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
2065 {
2066 	stbuf->f_type    = FUSE_SUPER_MAGIC;
2067 	stbuf->f_bsize   = attr->bsize;
2068 	stbuf->f_frsize  = attr->frsize;
2069 	stbuf->f_blocks  = attr->blocks;
2070 	stbuf->f_bfree   = attr->bfree;
2071 	stbuf->f_bavail  = attr->bavail;
2072 	stbuf->f_files   = attr->files;
2073 	stbuf->f_ffree   = attr->ffree;
2074 	stbuf->f_namelen = attr->namelen;
2075 	/* fsid is left zero */
2076 }
2077 
2078 #ifdef CONFIG_FUSE_BPF
2079 struct fuse_err_ret {
2080 	void *result;
2081 	bool ret;
2082 };
2083 
2084 int __init fuse_bpf_init(void);
2085 void __exit fuse_bpf_cleanup(void);
2086 
2087 ssize_t fuse_bpf_simple_request(struct fuse_mount *fm, struct fuse_bpf_args *args);
2088 
fuse_bpf_run(struct bpf_prog * prog,struct fuse_bpf_args * fba)2089 static inline int fuse_bpf_run(struct bpf_prog *prog, struct fuse_bpf_args *fba)
2090 {
2091 	int ret;
2092 
2093 	migrate_disable();
2094 	ret = bpf_prog_run(prog, fba);
2095 	migrate_enable();
2096 	return ret;
2097 }
2098 
2099 /*
2100  * expression statement to wrap the backing filter logic
2101  * struct inode *inode: inode with bpf and backing inode
2102  * typedef io: (typically complex) type whose components fuse_args can point to.
2103  *	An instance of this type is created locally and passed to initialize
2104  * void initialize(struct fuse_bpf_args *fa, io *in_out, args...): function that sets
2105  *	up fa and io based on args
2106  * int backing(struct fuse_bpf_args *fa, args...): function that actually performs
2107  *	the backing io operation
2108  * void *finalize(struct fuse_bpf_args *, args...): function that performs any final
2109  *	work needed to commit the backing io
2110  */
2111 #define fuse_bpf_backing(inode, io, initialize, backing, finalize,	\
2112 			 args...)					\
2113 ({									\
2114 	struct fuse_err_ret fer = {0};					\
2115 	int ext_flags;							\
2116 	struct fuse_inode *fuse_inode = get_fuse_inode(inode);		\
2117 	struct fuse_mount *fm = get_fuse_mount(inode);			\
2118 	io feo = {0};							\
2119 	struct fuse_bpf_args fa = {0}, fa_backup = {0};			\
2120 	bool locked;							\
2121 	ssize_t res;							\
2122 	void *err;							\
2123 	int i;								\
2124 	bool initialized = false;					\
2125 									\
2126 	do {								\
2127 		if (!fuse_inode || !fuse_inode->backing_inode)		\
2128 			break;						\
2129 									\
2130 		err = ERR_PTR(initialize(&fa, &feo, args));		\
2131 		if (err) {						\
2132 			fer = (struct fuse_err_ret) {			\
2133 				err,					\
2134 				true,					\
2135 			};						\
2136 			break;						\
2137 		}							\
2138 		initialized = true;					\
2139 									\
2140 		fa_backup = fa;						\
2141 		fa.opcode |= FUSE_PREFILTER;				\
2142 		for (i = 0; i < fa.in_numargs; ++i)			\
2143 			fa.out_args[i] = (struct fuse_bpf_arg) {	\
2144 				.size = fa.in_args[i].size,		\
2145 				.value = (void *)fa.in_args[i].value,	\
2146 			};						\
2147 		fa.out_numargs = fa.in_numargs;				\
2148 									\
2149 		ext_flags = fuse_inode->bpf ?				\
2150 			fuse_bpf_run(fuse_inode->bpf, &fa) :		\
2151 			FUSE_BPF_BACKING;				\
2152 		if (ext_flags < 0) {					\
2153 			fer = (struct fuse_err_ret) {			\
2154 				ERR_PTR(ext_flags),			\
2155 				true,					\
2156 			};						\
2157 			break;						\
2158 		}							\
2159 									\
2160 		if (ext_flags & FUSE_BPF_USER_FILTER) {			\
2161 			locked = fuse_lock_inode(inode);		\
2162 			res = fuse_bpf_simple_request(fm, &fa);		\
2163 			fuse_unlock_inode(inode, locked);		\
2164 			if (res < 0) {					\
2165 				fer = (struct fuse_err_ret) {		\
2166 					ERR_PTR(res),			\
2167 					true,				\
2168 				};					\
2169 				break;					\
2170 			}						\
2171 		}							\
2172 									\
2173 		if (!(ext_flags & FUSE_BPF_BACKING))			\
2174 			break;						\
2175 									\
2176 		fa.opcode &= ~FUSE_PREFILTER;				\
2177 		for (i = 0; i < fa.in_numargs; ++i)			\
2178 			fa.in_args[i] = (struct fuse_bpf_in_arg) {	\
2179 				.size = fa.out_args[i].size,		\
2180 				.value = fa.out_args[i].value,		\
2181 			};						\
2182 		for (i = 0; i < fa_backup.out_numargs; ++i)		\
2183 			fa.out_args[i] = (struct fuse_bpf_arg) {	\
2184 				.size = fa_backup.out_args[i].size,	\
2185 				.value = fa_backup.out_args[i].value,	\
2186 			};						\
2187 		fa.out_numargs = fa_backup.out_numargs;			\
2188 									\
2189 		fer = (struct fuse_err_ret) {				\
2190 			ERR_PTR(backing(&fa, args)),			\
2191 			true,						\
2192 		};							\
2193 		if (IS_ERR(fer.result))					\
2194 			fa.error_in = PTR_ERR(fer.result);		\
2195 		if (!(ext_flags & FUSE_BPF_POST_FILTER))		\
2196 			break;						\
2197 									\
2198 		fa.opcode |= FUSE_POSTFILTER;				\
2199 		for (i = 0; i < fa.out_numargs; ++i)			\
2200 			fa.in_args[fa.in_numargs++] =			\
2201 				(struct fuse_bpf_in_arg) {		\
2202 					.size = fa.out_args[i].size,	\
2203 					.value = fa.out_args[i].value,	\
2204 				};					\
2205 		ext_flags = fuse_bpf_run(fuse_inode->bpf, &fa);		\
2206 		if (ext_flags < 0) {					\
2207 			fer = (struct fuse_err_ret) {			\
2208 				ERR_PTR(ext_flags),			\
2209 				true,					\
2210 			};						\
2211 			break;						\
2212 		}							\
2213 		if (!(ext_flags & FUSE_BPF_USER_FILTER))		\
2214 			break;						\
2215 									\
2216 		fa.out_args[0].size = fa_backup.out_args[0].size;	\
2217 		fa.out_args[1].size = fa_backup.out_args[1].size;	\
2218 		fa.out_numargs = fa_backup.out_numargs;			\
2219 		locked = fuse_lock_inode(inode);			\
2220 		res = fuse_bpf_simple_request(fm, &fa);			\
2221 		fuse_unlock_inode(inode, locked);			\
2222 		if (res < 0) {						\
2223 			fer.result = ERR_PTR(res);			\
2224 			break;						\
2225 		}							\
2226 	} while (false);						\
2227 									\
2228 	if (initialized && fer.ret) {					\
2229 		err = finalize(&fa, args);				\
2230 		if (err)						\
2231 			fer.result = err;				\
2232 	}								\
2233 									\
2234 	fer;								\
2235 })
2236 
2237 #endif /* CONFIG_FUSE_BPF */
2238 
2239 #endif /* _FS_FUSE_I_H */
2240