1 /*
2 FUSE: Filesystem in Userspace
3 Copyright (C) 2001-2008 Miklos Szeredi <miklos@szeredi.hu>
4
5 This program can be distributed under the terms of the GNU GPL.
6 See the file COPYING.
7 */
8
9 #ifndef _FS_FUSE_I_H
10 #define _FS_FUSE_I_H
11
12 #ifndef pr_fmt
13 # define pr_fmt(fmt) "fuse: " fmt
14 #endif
15
16 #include <linux/fuse.h>
17 #include <linux/fs.h>
18 #include <linux/mount.h>
19 #include <linux/wait.h>
20 #include <linux/list.h>
21 #include <linux/spinlock.h>
22 #include <linux/mm.h>
23 #include <linux/backing-dev.h>
24 #include <linux/mutex.h>
25 #include <linux/rwsem.h>
26 #include <linux/rbtree.h>
27 #include <linux/poll.h>
28 #include <linux/workqueue.h>
29 #include <linux/kref.h>
30 #include <linux/xattr.h>
31 #include <linux/pid_namespace.h>
32 #include <linux/refcount.h>
33 #include <linux/user_namespace.h>
34
35 /** Default max number of pages that can be used in a single read request */
36 #define FUSE_DEFAULT_MAX_PAGES_PER_REQ 32
37
38 /** Maximum of max_pages received in init_out */
39 #define FUSE_MAX_MAX_PAGES 256
40
41 /** Bias for fi->writectr, meaning new writepages must not be sent */
42 #define FUSE_NOWRITE INT_MIN
43
44 /** It could be as large as PATH_MAX, but would that have any uses? */
45 #define FUSE_NAME_MAX 1024
46
47 /** Number of dentries for each connection in the control filesystem */
48 #define FUSE_CTL_NUM_DENTRIES 5
49
50 /** List of active connections */
51 extern struct list_head fuse_conn_list;
52
53 /** Global mutex protecting fuse_conn_list and the control filesystem */
54 extern struct mutex fuse_mutex;
55
56 /** Module parameters */
57 extern unsigned max_user_bgreq;
58 extern unsigned max_user_congthresh;
59
60 /* One forget request */
61 struct fuse_forget_link {
62 struct fuse_forget_one forget_one;
63 struct fuse_forget_link *next;
64 };
65
66 /** FUSE inode */
67 struct fuse_inode {
68 /** Inode data */
69 struct inode inode;
70
71 /** Unique ID, which identifies the inode between userspace
72 * and kernel */
73 u64 nodeid;
74
75 /** Number of lookups on this inode */
76 u64 nlookup;
77
78 /** The request used for sending the FORGET message */
79 struct fuse_forget_link *forget;
80
81 /** Time in jiffies until the file attributes are valid */
82 u64 i_time;
83
84 /* Which attributes are invalid */
85 u32 inval_mask;
86
87 /** The sticky bit in inode->i_mode may have been removed, so
88 preserve the original mode */
89 umode_t orig_i_mode;
90
91 /** 64 bit inode number */
92 u64 orig_ino;
93
94 /** Version of last attribute change */
95 u64 attr_version;
96
97 union {
98 /* Write related fields (regular file only) */
99 struct {
100 /* Files usable in writepage. Protected by fi->lock */
101 struct list_head write_files;
102
103 /* Writepages pending on truncate or fsync */
104 struct list_head queued_writes;
105
106 /* Number of sent writes, a negative bias
107 * (FUSE_NOWRITE) means more writes are blocked */
108 int writectr;
109
110 /* Waitq for writepage completion */
111 wait_queue_head_t page_waitq;
112
113 /* List of writepage requestst (pending or sent) */
114 struct rb_root writepages;
115 };
116
117 /* readdir cache (directory only) */
118 struct {
119 /* true if fully cached */
120 bool cached;
121
122 /* size of cache */
123 loff_t size;
124
125 /* position at end of cache (position of next entry) */
126 loff_t pos;
127
128 /* version of the cache */
129 u64 version;
130
131 /* modification time of directory when cache was
132 * started */
133 struct timespec64 mtime;
134
135 /* iversion of directory when cache was started */
136 u64 iversion;
137
138 /* protects above fields */
139 spinlock_t lock;
140 } rdc;
141 };
142
143 /** Miscellaneous bits describing inode state */
144 unsigned long state;
145
146 /** Lock for serializing lookup and readdir for back compatibility*/
147 struct mutex mutex;
148
149 /** Lock to protect write related fields */
150 spinlock_t lock;
151
152 #ifdef CONFIG_FUSE_DAX
153 /*
154 * Dax specific inode data
155 */
156 struct fuse_inode_dax *dax;
157 #endif
158 };
159
160 /** FUSE inode state bits */
161 enum {
162 /** Advise readdirplus */
163 FUSE_I_ADVISE_RDPLUS,
164 /** Initialized with readdirplus */
165 FUSE_I_INIT_RDPLUS,
166 /** An operation changing file size is in progress */
167 FUSE_I_SIZE_UNSTABLE,
168 /* Bad inode */
169 FUSE_I_BAD,
170 };
171
172 struct fuse_conn;
173 struct fuse_mount;
174 struct fuse_release_args;
175
176 /** FUSE specific file data */
177 struct fuse_file {
178 /** Fuse connection for this file */
179 struct fuse_mount *fm;
180
181 /* Argument space reserved for release */
182 struct fuse_release_args *release_args;
183
184 /** Kernel file handle guaranteed to be unique */
185 u64 kh;
186
187 /** File handle used by userspace */
188 u64 fh;
189
190 /** Node id of this file */
191 u64 nodeid;
192
193 /** Refcount */
194 refcount_t count;
195
196 /** FOPEN_* flags returned by open */
197 u32 open_flags;
198
199 /** Entry on inode's write_files list */
200 struct list_head write_entry;
201
202 /* Readdir related */
203 struct {
204 /*
205 * Protects below fields against (crazy) parallel readdir on
206 * same open file. Uncontended in the normal case.
207 */
208 struct mutex lock;
209
210 /* Dir stream position */
211 loff_t pos;
212
213 /* Offset in cache */
214 loff_t cache_off;
215
216 /* Version of cache we are reading */
217 u64 version;
218
219 } readdir;
220
221 /** RB node to be linked on fuse_conn->polled_files */
222 struct rb_node polled_node;
223
224 /** Wait queue head for poll */
225 wait_queue_head_t poll_wait;
226
227 /** Has flock been performed on this file? */
228 bool flock:1;
229 };
230
231 /** One input argument of a request */
232 struct fuse_in_arg {
233 unsigned size;
234 const void *value;
235 };
236
237 /** One output argument of a request */
238 struct fuse_arg {
239 unsigned size;
240 void *value;
241 };
242
243 /** FUSE page descriptor */
244 struct fuse_page_desc {
245 unsigned int length;
246 unsigned int offset;
247 };
248
249 struct fuse_args {
250 uint64_t nodeid;
251 uint32_t opcode;
252 unsigned short in_numargs;
253 unsigned short out_numargs;
254 bool force:1;
255 bool noreply:1;
256 bool nocreds:1;
257 bool in_pages:1;
258 bool out_pages:1;
259 bool user_pages:1;
260 bool out_argvar:1;
261 bool page_zeroing:1;
262 bool page_replace:1;
263 bool may_block:1;
264 struct fuse_in_arg in_args[3];
265 struct fuse_arg out_args[2];
266 void (*end)(struct fuse_mount *fm, struct fuse_args *args, int error);
267 };
268
269 struct fuse_args_pages {
270 struct fuse_args args;
271 struct page **pages;
272 struct fuse_page_desc *descs;
273 unsigned int num_pages;
274 };
275
276 #define FUSE_ARGS(args) struct fuse_args args = {}
277
278 /** The request IO state (for asynchronous processing) */
279 struct fuse_io_priv {
280 struct kref refcnt;
281 int async;
282 spinlock_t lock;
283 unsigned reqs;
284 ssize_t bytes;
285 size_t size;
286 __u64 offset;
287 bool write;
288 bool should_dirty;
289 int err;
290 struct kiocb *iocb;
291 struct completion *done;
292 bool blocking;
293 };
294
295 #define FUSE_IO_PRIV_SYNC(i) \
296 { \
297 .refcnt = KREF_INIT(1), \
298 .async = 0, \
299 .iocb = i, \
300 }
301
302 /**
303 * Request flags
304 *
305 * FR_ISREPLY: set if the request has reply
306 * FR_FORCE: force sending of the request even if interrupted
307 * FR_BACKGROUND: request is sent in the background
308 * FR_WAITING: request is counted as "waiting"
309 * FR_ABORTED: the request was aborted
310 * FR_INTERRUPTED: the request has been interrupted
311 * FR_LOCKED: data is being copied to/from the request
312 * FR_PENDING: request is not yet in userspace
313 * FR_SENT: request is in userspace, waiting for an answer
314 * FR_FINISHED: request is finished
315 * FR_PRIVATE: request is on private list
316 * FR_ASYNC: request is asynchronous
317 */
318 enum fuse_req_flag {
319 FR_ISREPLY,
320 FR_FORCE,
321 FR_BACKGROUND,
322 FR_WAITING,
323 FR_ABORTED,
324 FR_INTERRUPTED,
325 FR_LOCKED,
326 FR_PENDING,
327 FR_SENT,
328 FR_FINISHED,
329 FR_PRIVATE,
330 FR_ASYNC,
331 };
332
333 /**
334 * A request to the client
335 *
336 * .waitq.lock protects the following fields:
337 * - FR_ABORTED
338 * - FR_LOCKED (may also be modified under fc->lock, tested under both)
339 */
340 struct fuse_req {
341 /** This can be on either pending processing or io lists in
342 fuse_conn */
343 struct list_head list;
344
345 /** Entry on the interrupts list */
346 struct list_head intr_entry;
347
348 /* Input/output arguments */
349 struct fuse_args *args;
350
351 /** refcount */
352 refcount_t count;
353
354 /* Request flags, updated with test/set/clear_bit() */
355 unsigned long flags;
356
357 /* The request input header */
358 struct {
359 struct fuse_in_header h;
360 } in;
361
362 /* The request output header */
363 struct {
364 struct fuse_out_header h;
365 } out;
366
367 /** Used to wake up the task waiting for completion of request*/
368 wait_queue_head_t waitq;
369
370 #if IS_ENABLED(CONFIG_VIRTIO_FS)
371 /** virtio-fs's physically contiguous buffer for in and out args */
372 void *argbuf;
373 #endif
374
375 /** fuse_mount this request belongs to */
376 struct fuse_mount *fm;
377 };
378
379 struct fuse_iqueue;
380
381 /**
382 * Input queue callbacks
383 *
384 * Input queue signalling is device-specific. For example, the /dev/fuse file
385 * uses fiq->waitq and fasync to wake processes that are waiting on queue
386 * readiness. These callbacks allow other device types to respond to input
387 * queue activity.
388 */
389 struct fuse_iqueue_ops {
390 /**
391 * Signal that a forget has been queued
392 */
393 void (*wake_forget_and_unlock)(struct fuse_iqueue *fiq)
394 __releases(fiq->lock);
395
396 /**
397 * Signal that an INTERRUPT request has been queued
398 */
399 void (*wake_interrupt_and_unlock)(struct fuse_iqueue *fiq)
400 __releases(fiq->lock);
401
402 /**
403 * Signal that a request has been queued
404 */
405 void (*wake_pending_and_unlock)(struct fuse_iqueue *fiq)
406 __releases(fiq->lock);
407
408 /**
409 * Clean up when fuse_iqueue is destroyed
410 */
411 void (*release)(struct fuse_iqueue *fiq);
412 };
413
414 /** /dev/fuse input queue operations */
415 extern const struct fuse_iqueue_ops fuse_dev_fiq_ops;
416
417 struct fuse_iqueue {
418 /** Connection established */
419 unsigned connected;
420
421 /** Lock protecting accesses to members of this structure */
422 spinlock_t lock;
423
424 /** Readers of the connection are waiting on this */
425 wait_queue_head_t waitq;
426
427 /** The next unique request id */
428 u64 reqctr;
429
430 /** The list of pending requests */
431 struct list_head pending;
432
433 /** Pending interrupts */
434 struct list_head interrupts;
435
436 /** Queue of pending forgets */
437 struct fuse_forget_link forget_list_head;
438 struct fuse_forget_link *forget_list_tail;
439
440 /** Batching of FORGET requests (positive indicates FORGET batch) */
441 int forget_batch;
442
443 /** O_ASYNC requests */
444 struct fasync_struct *fasync;
445
446 /** Device-specific callbacks */
447 const struct fuse_iqueue_ops *ops;
448
449 /** Device-specific state */
450 void *priv;
451 };
452
453 #define FUSE_PQ_HASH_BITS 8
454 #define FUSE_PQ_HASH_SIZE (1 << FUSE_PQ_HASH_BITS)
455
456 struct fuse_pqueue {
457 /** Connection established */
458 unsigned connected;
459
460 /** Lock protecting accessess to members of this structure */
461 spinlock_t lock;
462
463 /** Hash table of requests being processed */
464 struct list_head *processing;
465
466 /** The list of requests under I/O */
467 struct list_head io;
468 };
469
470 /**
471 * Fuse device instance
472 */
473 struct fuse_dev {
474 /** Fuse connection for this device */
475 struct fuse_conn *fc;
476
477 /** Processing queue */
478 struct fuse_pqueue pq;
479
480 /** list entry on fc->devices */
481 struct list_head entry;
482 };
483
484 enum fuse_dax_mode {
485 FUSE_DAX_INODE_DEFAULT, /* default */
486 FUSE_DAX_ALWAYS, /* "-o dax=always" */
487 FUSE_DAX_NEVER, /* "-o dax=never" */
488 FUSE_DAX_INODE_USER, /* "-o dax=inode" */
489 };
490
fuse_is_inode_dax_mode(enum fuse_dax_mode mode)491 static inline bool fuse_is_inode_dax_mode(enum fuse_dax_mode mode)
492 {
493 return mode == FUSE_DAX_INODE_DEFAULT || mode == FUSE_DAX_INODE_USER;
494 }
495
496 struct fuse_fs_context {
497 int fd;
498 struct file *file;
499 unsigned int rootmode;
500 kuid_t user_id;
501 kgid_t group_id;
502 bool is_bdev:1;
503 bool fd_present:1;
504 bool rootmode_present:1;
505 bool user_id_present:1;
506 bool group_id_present:1;
507 bool default_permissions:1;
508 bool allow_other:1;
509 bool destroy:1;
510 bool no_control:1;
511 bool no_force_umount:1;
512 bool legacy_opts_show:1;
513 enum fuse_dax_mode dax_mode;
514 unsigned int max_read;
515 unsigned int blksize;
516 const char *subtype;
517
518 /* DAX device, may be NULL */
519 struct dax_device *dax_dev;
520
521 /* fuse_dev pointer to fill in, should contain NULL on entry */
522 void **fudptr;
523 };
524
525 struct fuse_sync_bucket {
526 /* count is a possible scalability bottleneck */
527 atomic_t count;
528 wait_queue_head_t waitq;
529 struct rcu_head rcu;
530 };
531
532 /**
533 * A Fuse connection.
534 *
535 * This structure is created, when the root filesystem is mounted, and
536 * is destroyed, when the client device is closed and the last
537 * fuse_mount is destroyed.
538 */
539 struct fuse_conn {
540 /** Lock protecting accessess to members of this structure */
541 spinlock_t lock;
542
543 /** Refcount */
544 refcount_t count;
545
546 /** Number of fuse_dev's */
547 atomic_t dev_count;
548
549 struct rcu_head rcu;
550
551 /** The user id for this mount */
552 kuid_t user_id;
553
554 /** The group id for this mount */
555 kgid_t group_id;
556
557 /** The pid namespace for this mount */
558 struct pid_namespace *pid_ns;
559
560 /** The user namespace for this mount */
561 struct user_namespace *user_ns;
562
563 /** Maximum read size */
564 unsigned max_read;
565
566 /** Maximum write size */
567 unsigned max_write;
568
569 /** Maximum number of pages that can be used in a single request */
570 unsigned int max_pages;
571
572 /** Constrain ->max_pages to this value during feature negotiation */
573 unsigned int max_pages_limit;
574
575 /** Input queue */
576 struct fuse_iqueue iq;
577
578 /** The next unique kernel file handle */
579 atomic64_t khctr;
580
581 /** rbtree of fuse_files waiting for poll events indexed by ph */
582 struct rb_root polled_files;
583
584 /** Maximum number of outstanding background requests */
585 unsigned max_background;
586
587 /** Number of background requests at which congestion starts */
588 unsigned congestion_threshold;
589
590 /** Number of requests currently in the background */
591 unsigned num_background;
592
593 /** Number of background requests currently queued for userspace */
594 unsigned active_background;
595
596 /** The list of background requests set aside for later queuing */
597 struct list_head bg_queue;
598
599 /** Protects: max_background, congestion_threshold, num_background,
600 * active_background, bg_queue, blocked */
601 spinlock_t bg_lock;
602
603 /** Flag indicating that INIT reply has been received. Allocating
604 * any fuse request will be suspended until the flag is set */
605 int initialized;
606
607 /** Flag indicating if connection is blocked. This will be
608 the case before the INIT reply is received, and if there
609 are too many outstading backgrounds requests */
610 int blocked;
611
612 /** waitq for blocked connection */
613 wait_queue_head_t blocked_waitq;
614
615 /** Connection established, cleared on umount, connection
616 abort and device release */
617 unsigned connected;
618
619 /** Connection aborted via sysfs */
620 bool aborted;
621
622 /** Connection failed (version mismatch). Cannot race with
623 setting other bitfields since it is only set once in INIT
624 reply, before any other request, and never cleared */
625 unsigned conn_error:1;
626
627 /** Connection successful. Only set in INIT */
628 unsigned conn_init:1;
629
630 /** Do readahead asynchronously? Only set in INIT */
631 unsigned async_read:1;
632
633 /** Return an unique read error after abort. Only set in INIT */
634 unsigned abort_err:1;
635
636 /** Do not send separate SETATTR request before open(O_TRUNC) */
637 unsigned atomic_o_trunc:1;
638
639 /** Filesystem supports NFS exporting. Only set in INIT */
640 unsigned export_support:1;
641
642 /** write-back cache policy (default is write-through) */
643 unsigned writeback_cache:1;
644
645 /** allow parallel lookups and readdir (default is serialized) */
646 unsigned parallel_dirops:1;
647
648 /** handle fs handles killing suid/sgid/cap on write/chown/trunc */
649 unsigned handle_killpriv:1;
650
651 /** cache READLINK responses in page cache */
652 unsigned cache_symlinks:1;
653
654 /* show legacy mount options */
655 unsigned int legacy_opts_show:1;
656
657 /*
658 * fs kills suid/sgid/cap on write/chown/trunc. suid is killed on
659 * write/trunc only if caller did not have CAP_FSETID. sgid is killed
660 * on write/truncate only if caller did not have CAP_FSETID as well as
661 * file has group execute permission.
662 */
663 unsigned handle_killpriv_v2:1;
664
665 /*
666 * The following bitfields are only for optimization purposes
667 * and hence races in setting them will not cause malfunction
668 */
669
670 /** Is open/release not implemented by fs? */
671 unsigned no_open:1;
672
673 /** Is opendir/releasedir not implemented by fs? */
674 unsigned no_opendir:1;
675
676 /** Is fsync not implemented by fs? */
677 unsigned no_fsync:1;
678
679 /** Is fsyncdir not implemented by fs? */
680 unsigned no_fsyncdir:1;
681
682 /** Is flush not implemented by fs? */
683 unsigned no_flush:1;
684
685 /** Is setxattr not implemented by fs? */
686 unsigned no_setxattr:1;
687
688 /** Does file server support extended setxattr */
689 unsigned setxattr_ext:1;
690
691 /** Is getxattr not implemented by fs? */
692 unsigned no_getxattr:1;
693
694 /** Is listxattr not implemented by fs? */
695 unsigned no_listxattr:1;
696
697 /** Is removexattr not implemented by fs? */
698 unsigned no_removexattr:1;
699
700 /** Are posix file locking primitives not implemented by fs? */
701 unsigned no_lock:1;
702
703 /** Is access not implemented by fs? */
704 unsigned no_access:1;
705
706 /** Is create not implemented by fs? */
707 unsigned no_create:1;
708
709 /** Is interrupt not implemented by fs? */
710 unsigned no_interrupt:1;
711
712 /** Is bmap not implemented by fs? */
713 unsigned no_bmap:1;
714
715 /** Is poll not implemented by fs? */
716 unsigned no_poll:1;
717
718 /** Do multi-page cached writes */
719 unsigned big_writes:1;
720
721 /** Don't apply umask to creation modes */
722 unsigned dont_mask:1;
723
724 /** Are BSD file locking primitives not implemented by fs? */
725 unsigned no_flock:1;
726
727 /** Is fallocate not implemented by fs? */
728 unsigned no_fallocate:1;
729
730 /** Is rename with flags implemented by fs? */
731 unsigned no_rename2:1;
732
733 /** Use enhanced/automatic page cache invalidation. */
734 unsigned auto_inval_data:1;
735
736 /** Filesystem is fully responsible for page cache invalidation. */
737 unsigned explicit_inval_data:1;
738
739 /** Does the filesystem support readdirplus? */
740 unsigned do_readdirplus:1;
741
742 /** Does the filesystem want adaptive readdirplus? */
743 unsigned readdirplus_auto:1;
744
745 /** Does the filesystem support asynchronous direct-IO submission? */
746 unsigned async_dio:1;
747
748 /** Is lseek not implemented by fs? */
749 unsigned no_lseek:1;
750
751 /** Does the filesystem support posix acls? */
752 unsigned posix_acl:1;
753
754 /** Check permissions based on the file mode or not? */
755 unsigned default_permissions:1;
756
757 /** Allow other than the mounter user to access the filesystem ? */
758 unsigned allow_other:1;
759
760 /** Does the filesystem support copy_file_range? */
761 unsigned no_copy_file_range:1;
762
763 /* Send DESTROY request */
764 unsigned int destroy:1;
765
766 /* Delete dentries that have gone stale */
767 unsigned int delete_stale:1;
768
769 /** Do not create entry in fusectl fs */
770 unsigned int no_control:1;
771
772 /** Do not allow MNT_FORCE umount */
773 unsigned int no_force_umount:1;
774
775 /* Auto-mount submounts announced by the server */
776 unsigned int auto_submounts:1;
777
778 /* Propagate syncfs() to server */
779 unsigned int sync_fs:1;
780
781 /* Initialize security xattrs when creating a new inode */
782 unsigned int init_security:1;
783
784 /* Does the filesystem support per inode DAX? */
785 unsigned int inode_dax:1;
786
787 /* Is tmpfile not implemented by fs? */
788 unsigned int no_tmpfile:1;
789
790 /** The number of requests waiting for completion */
791 atomic_t num_waiting;
792
793 /** Negotiated minor version */
794 unsigned minor;
795
796 /** Entry on the fuse_mount_list */
797 struct list_head entry;
798
799 /** Device ID from the root super block */
800 dev_t dev;
801
802 /** Dentries in the control filesystem */
803 struct dentry *ctl_dentry[FUSE_CTL_NUM_DENTRIES];
804
805 /** number of dentries used in the above array */
806 int ctl_ndents;
807
808 /** Key for lock owner ID scrambling */
809 u32 scramble_key[4];
810
811 /** Version counter for attribute changes */
812 atomic64_t attr_version;
813
814 /** Called on final put */
815 void (*release)(struct fuse_conn *);
816
817 /**
818 * Read/write semaphore to hold when accessing the sb of any
819 * fuse_mount belonging to this connection
820 */
821 struct rw_semaphore killsb;
822
823 /** List of device instances belonging to this connection */
824 struct list_head devices;
825
826 #ifdef CONFIG_FUSE_DAX
827 /* Dax mode */
828 enum fuse_dax_mode dax_mode;
829
830 /* Dax specific conn data, non-NULL if DAX is enabled */
831 struct fuse_conn_dax *dax;
832 #endif
833
834 /** List of filesystems using this connection */
835 struct list_head mounts;
836
837 /* New writepages go into this bucket */
838 struct fuse_sync_bucket __rcu *curr_bucket;
839 };
840
841 /*
842 * Represents a mounted filesystem, potentially a submount.
843 *
844 * This object allows sharing a fuse_conn between separate mounts to
845 * allow submounts with dedicated superblocks and thus separate device
846 * IDs.
847 */
848 struct fuse_mount {
849 /* Underlying (potentially shared) connection to the FUSE server */
850 struct fuse_conn *fc;
851
852 /*
853 * Super block for this connection (fc->killsb must be held when
854 * accessing this).
855 */
856 struct super_block *sb;
857
858 /* Entry on fc->mounts */
859 struct list_head fc_entry;
860 };
861
get_fuse_mount_super(struct super_block * sb)862 static inline struct fuse_mount *get_fuse_mount_super(struct super_block *sb)
863 {
864 return sb->s_fs_info;
865 }
866
get_fuse_conn_super(struct super_block * sb)867 static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
868 {
869 return get_fuse_mount_super(sb)->fc;
870 }
871
get_fuse_mount(struct inode * inode)872 static inline struct fuse_mount *get_fuse_mount(struct inode *inode)
873 {
874 return get_fuse_mount_super(inode->i_sb);
875 }
876
get_fuse_conn(struct inode * inode)877 static inline struct fuse_conn *get_fuse_conn(struct inode *inode)
878 {
879 return get_fuse_mount_super(inode->i_sb)->fc;
880 }
881
get_fuse_inode(struct inode * inode)882 static inline struct fuse_inode *get_fuse_inode(struct inode *inode)
883 {
884 return container_of(inode, struct fuse_inode, inode);
885 }
886
get_node_id(struct inode * inode)887 static inline u64 get_node_id(struct inode *inode)
888 {
889 return get_fuse_inode(inode)->nodeid;
890 }
891
invalid_nodeid(u64 nodeid)892 static inline int invalid_nodeid(u64 nodeid)
893 {
894 return !nodeid || nodeid == FUSE_ROOT_ID;
895 }
896
fuse_get_attr_version(struct fuse_conn * fc)897 static inline u64 fuse_get_attr_version(struct fuse_conn *fc)
898 {
899 return atomic64_read(&fc->attr_version);
900 }
901
fuse_stale_inode(const struct inode * inode,int generation,struct fuse_attr * attr)902 static inline bool fuse_stale_inode(const struct inode *inode, int generation,
903 struct fuse_attr *attr)
904 {
905 return inode->i_generation != generation ||
906 inode_wrong_type(inode, attr->mode);
907 }
908
fuse_make_bad(struct inode * inode)909 static inline void fuse_make_bad(struct inode *inode)
910 {
911 remove_inode_hash(inode);
912 set_bit(FUSE_I_BAD, &get_fuse_inode(inode)->state);
913 }
914
fuse_is_bad(struct inode * inode)915 static inline bool fuse_is_bad(struct inode *inode)
916 {
917 return unlikely(test_bit(FUSE_I_BAD, &get_fuse_inode(inode)->state));
918 }
919
fuse_pages_alloc(unsigned int npages,gfp_t flags,struct fuse_page_desc ** desc)920 static inline struct page **fuse_pages_alloc(unsigned int npages, gfp_t flags,
921 struct fuse_page_desc **desc)
922 {
923 struct page **pages;
924
925 pages = kzalloc(npages * (sizeof(struct page *) +
926 sizeof(struct fuse_page_desc)), flags);
927 *desc = (void *) (pages + npages);
928
929 return pages;
930 }
931
fuse_page_descs_length_init(struct fuse_page_desc * descs,unsigned int index,unsigned int nr_pages)932 static inline void fuse_page_descs_length_init(struct fuse_page_desc *descs,
933 unsigned int index,
934 unsigned int nr_pages)
935 {
936 int i;
937
938 for (i = index; i < index + nr_pages; i++)
939 descs[i].length = PAGE_SIZE - descs[i].offset;
940 }
941
fuse_sync_bucket_dec(struct fuse_sync_bucket * bucket)942 static inline void fuse_sync_bucket_dec(struct fuse_sync_bucket *bucket)
943 {
944 /* Need RCU protection to prevent use after free after the decrement */
945 rcu_read_lock();
946 if (atomic_dec_and_test(&bucket->count))
947 wake_up(&bucket->waitq);
948 rcu_read_unlock();
949 }
950
951 /** Device operations */
952 extern const struct file_operations fuse_dev_operations;
953
954 extern const struct dentry_operations fuse_dentry_operations;
955 extern const struct dentry_operations fuse_root_dentry_operations;
956
957 /**
958 * Get a filled in inode
959 */
960 struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
961 int generation, struct fuse_attr *attr,
962 u64 attr_valid, u64 attr_version);
963
964 int fuse_lookup_name(struct super_block *sb, u64 nodeid, const struct qstr *name,
965 struct fuse_entry_out *outarg, struct inode **inode);
966
967 /**
968 * Send FORGET command
969 */
970 void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget,
971 u64 nodeid, u64 nlookup);
972
973 struct fuse_forget_link *fuse_alloc_forget(void);
974
975 struct fuse_forget_link *fuse_dequeue_forget(struct fuse_iqueue *fiq,
976 unsigned int max,
977 unsigned int *countp);
978
979 /*
980 * Initialize READ or READDIR request
981 */
982 struct fuse_io_args {
983 union {
984 struct {
985 struct fuse_read_in in;
986 u64 attr_ver;
987 } read;
988 struct {
989 struct fuse_write_in in;
990 struct fuse_write_out out;
991 bool page_locked;
992 } write;
993 };
994 struct fuse_args_pages ap;
995 struct fuse_io_priv *io;
996 struct fuse_file *ff;
997 };
998
999 void fuse_read_args_fill(struct fuse_io_args *ia, struct file *file, loff_t pos,
1000 size_t count, int opcode);
1001
1002
1003 /**
1004 * Send OPEN or OPENDIR request
1005 */
1006 int fuse_open_common(struct inode *inode, struct file *file, bool isdir);
1007
1008 struct fuse_file *fuse_file_alloc(struct fuse_mount *fm);
1009 void fuse_file_free(struct fuse_file *ff);
1010 void fuse_finish_open(struct inode *inode, struct file *file);
1011
1012 void fuse_sync_release(struct fuse_inode *fi, struct fuse_file *ff,
1013 unsigned int flags);
1014
1015 /**
1016 * Send RELEASE or RELEASEDIR request
1017 */
1018 void fuse_release_common(struct file *file, bool isdir);
1019
1020 /**
1021 * Send FSYNC or FSYNCDIR request
1022 */
1023 int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
1024 int datasync, int opcode);
1025
1026 /**
1027 * Notify poll wakeup
1028 */
1029 int fuse_notify_poll_wakeup(struct fuse_conn *fc,
1030 struct fuse_notify_poll_wakeup_out *outarg);
1031
1032 /**
1033 * Initialize file operations on a regular file
1034 */
1035 void fuse_init_file_inode(struct inode *inode, unsigned int flags);
1036
1037 /**
1038 * Initialize inode operations on regular files and special files
1039 */
1040 void fuse_init_common(struct inode *inode);
1041
1042 /**
1043 * Initialize inode and file operations on a directory
1044 */
1045 void fuse_init_dir(struct inode *inode);
1046
1047 /**
1048 * Initialize inode operations on a symlink
1049 */
1050 void fuse_init_symlink(struct inode *inode);
1051
1052 /**
1053 * Change attributes of an inode
1054 */
1055 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
1056 u64 attr_valid, u64 attr_version);
1057
1058 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
1059 u64 attr_valid, u32 cache_mask);
1060
1061 u32 fuse_get_cache_mask(struct inode *inode);
1062
1063 /**
1064 * Initialize the client device
1065 */
1066 int fuse_dev_init(void);
1067
1068 /**
1069 * Cleanup the client device
1070 */
1071 void fuse_dev_cleanup(void);
1072
1073 int fuse_ctl_init(void);
1074 void __exit fuse_ctl_cleanup(void);
1075
1076 /**
1077 * Simple request sending that does request allocation and freeing
1078 */
1079 ssize_t fuse_simple_request(struct fuse_mount *fm, struct fuse_args *args);
1080 int fuse_simple_background(struct fuse_mount *fm, struct fuse_args *args,
1081 gfp_t gfp_flags);
1082
1083 /**
1084 * End a finished request
1085 */
1086 void fuse_request_end(struct fuse_req *req);
1087
1088 /* Abort all requests */
1089 void fuse_abort_conn(struct fuse_conn *fc);
1090 void fuse_wait_aborted(struct fuse_conn *fc);
1091
1092 /**
1093 * Invalidate inode attributes
1094 */
1095
1096 /* Attributes possibly changed on data modification */
1097 #define FUSE_STATX_MODIFY (STATX_MTIME | STATX_CTIME | STATX_BLOCKS)
1098
1099 /* Attributes possibly changed on data and/or size modification */
1100 #define FUSE_STATX_MODSIZE (FUSE_STATX_MODIFY | STATX_SIZE)
1101
1102 void fuse_invalidate_attr(struct inode *inode);
1103 void fuse_invalidate_attr_mask(struct inode *inode, u32 mask);
1104
1105 void fuse_invalidate_entry_cache(struct dentry *entry);
1106
1107 void fuse_invalidate_atime(struct inode *inode);
1108
1109 u64 entry_attr_timeout(struct fuse_entry_out *o);
1110 void fuse_change_entry_timeout(struct dentry *entry, struct fuse_entry_out *o);
1111
1112 /**
1113 * Acquire reference to fuse_conn
1114 */
1115 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc);
1116
1117 /**
1118 * Initialize fuse_conn
1119 */
1120 void fuse_conn_init(struct fuse_conn *fc, struct fuse_mount *fm,
1121 struct user_namespace *user_ns,
1122 const struct fuse_iqueue_ops *fiq_ops, void *fiq_priv);
1123
1124 /**
1125 * Release reference to fuse_conn
1126 */
1127 void fuse_conn_put(struct fuse_conn *fc);
1128
1129 struct fuse_dev *fuse_dev_alloc_install(struct fuse_conn *fc);
1130 struct fuse_dev *fuse_dev_alloc(void);
1131 void fuse_dev_install(struct fuse_dev *fud, struct fuse_conn *fc);
1132 void fuse_dev_free(struct fuse_dev *fud);
1133 void fuse_send_init(struct fuse_mount *fm);
1134
1135 /**
1136 * Fill in superblock and initialize fuse connection
1137 * @sb: partially-initialized superblock to fill in
1138 * @ctx: mount context
1139 */
1140 int fuse_fill_super_common(struct super_block *sb, struct fuse_fs_context *ctx);
1141
1142 /*
1143 * Remove the mount from the connection
1144 *
1145 * Returns whether this was the last mount
1146 */
1147 bool fuse_mount_remove(struct fuse_mount *fm);
1148
1149 /*
1150 * Setup context ops for submounts
1151 */
1152 int fuse_init_fs_context_submount(struct fs_context *fsc);
1153
1154 /*
1155 * Shut down the connection (possibly sending DESTROY request).
1156 */
1157 void fuse_conn_destroy(struct fuse_mount *fm);
1158
1159 /* Drop the connection and free the fuse mount */
1160 void fuse_mount_destroy(struct fuse_mount *fm);
1161
1162 /**
1163 * Add connection to control filesystem
1164 */
1165 int fuse_ctl_add_conn(struct fuse_conn *fc);
1166
1167 /**
1168 * Remove connection from control filesystem
1169 */
1170 void fuse_ctl_remove_conn(struct fuse_conn *fc);
1171
1172 /**
1173 * Is file type valid?
1174 */
1175 int fuse_valid_type(int m);
1176
1177 bool fuse_invalid_attr(struct fuse_attr *attr);
1178
1179 /**
1180 * Is current process allowed to perform filesystem operation?
1181 */
1182 int fuse_allow_current_process(struct fuse_conn *fc);
1183
1184 u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id);
1185
1186 void fuse_flush_time_update(struct inode *inode);
1187 void fuse_update_ctime(struct inode *inode);
1188
1189 int fuse_update_attributes(struct inode *inode, struct file *file, u32 mask);
1190
1191 void fuse_flush_writepages(struct inode *inode);
1192
1193 void fuse_set_nowrite(struct inode *inode);
1194 void fuse_release_nowrite(struct inode *inode);
1195
1196 /**
1197 * Scan all fuse_mounts belonging to fc to find the first where
1198 * ilookup5() returns a result. Return that result and the
1199 * respective fuse_mount in *fm (unless fm is NULL).
1200 *
1201 * The caller must hold fc->killsb.
1202 */
1203 struct inode *fuse_ilookup(struct fuse_conn *fc, u64 nodeid,
1204 struct fuse_mount **fm);
1205
1206 /**
1207 * File-system tells the kernel to invalidate cache for the given node id.
1208 */
1209 int fuse_reverse_inval_inode(struct fuse_conn *fc, u64 nodeid,
1210 loff_t offset, loff_t len);
1211
1212 /**
1213 * File-system tells the kernel to invalidate parent attributes and
1214 * the dentry matching parent/name.
1215 *
1216 * If the child_nodeid is non-zero and:
1217 * - matches the inode number for the dentry matching parent/name,
1218 * - is not a mount point
1219 * - is a file or oan empty directory
1220 * then the dentry is unhashed (d_delete()).
1221 */
1222 int fuse_reverse_inval_entry(struct fuse_conn *fc, u64 parent_nodeid,
1223 u64 child_nodeid, struct qstr *name);
1224
1225 int fuse_do_open(struct fuse_mount *fm, u64 nodeid, struct file *file,
1226 bool isdir);
1227
1228 /**
1229 * fuse_direct_io() flags
1230 */
1231
1232 /** If set, it is WRITE; otherwise - READ */
1233 #define FUSE_DIO_WRITE (1 << 0)
1234
1235 /** CUSE pass fuse_direct_io() a file which f_mapping->host is not from FUSE */
1236 #define FUSE_DIO_CUSE (1 << 1)
1237
1238 ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter,
1239 loff_t *ppos, int flags);
1240 long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
1241 unsigned int flags);
1242 long fuse_ioctl_common(struct file *file, unsigned int cmd,
1243 unsigned long arg, unsigned int flags);
1244 __poll_t fuse_file_poll(struct file *file, poll_table *wait);
1245 int fuse_dev_release(struct inode *inode, struct file *file);
1246
1247 bool fuse_write_update_attr(struct inode *inode, loff_t pos, ssize_t written);
1248
1249 int fuse_flush_times(struct inode *inode, struct fuse_file *ff);
1250 int fuse_write_inode(struct inode *inode, struct writeback_control *wbc);
1251
1252 int fuse_do_setattr(struct dentry *dentry, struct iattr *attr,
1253 struct file *file);
1254
1255 void fuse_set_initialized(struct fuse_conn *fc);
1256
1257 void fuse_unlock_inode(struct inode *inode, bool locked);
1258 bool fuse_lock_inode(struct inode *inode);
1259
1260 int fuse_setxattr(struct inode *inode, const char *name, const void *value,
1261 size_t size, int flags, unsigned int extra_flags);
1262 ssize_t fuse_getxattr(struct inode *inode, const char *name, void *value,
1263 size_t size);
1264 ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size);
1265 int fuse_removexattr(struct inode *inode, const char *name);
1266 extern const struct xattr_handler *fuse_xattr_handlers[];
1267 extern const struct xattr_handler *fuse_acl_xattr_handlers[];
1268 extern const struct xattr_handler *fuse_no_acl_xattr_handlers[];
1269
1270 struct posix_acl;
1271 struct posix_acl *fuse_get_acl(struct inode *inode, int type, bool rcu);
1272 int fuse_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
1273 struct posix_acl *acl, int type);
1274
1275 /* readdir.c */
1276 int fuse_readdir(struct file *file, struct dir_context *ctx);
1277
1278 /**
1279 * Return the number of bytes in an arguments list
1280 */
1281 unsigned int fuse_len_args(unsigned int numargs, struct fuse_arg *args);
1282
1283 /**
1284 * Get the next unique ID for a request
1285 */
1286 u64 fuse_get_unique(struct fuse_iqueue *fiq);
1287 void fuse_free_conn(struct fuse_conn *fc);
1288
1289 /* dax.c */
1290
1291 #define FUSE_IS_DAX(inode) (IS_ENABLED(CONFIG_FUSE_DAX) && IS_DAX(inode))
1292
1293 ssize_t fuse_dax_read_iter(struct kiocb *iocb, struct iov_iter *to);
1294 ssize_t fuse_dax_write_iter(struct kiocb *iocb, struct iov_iter *from);
1295 int fuse_dax_mmap(struct file *file, struct vm_area_struct *vma);
1296 int fuse_dax_break_layouts(struct inode *inode, u64 dmap_start, u64 dmap_end);
1297 int fuse_dax_conn_alloc(struct fuse_conn *fc, enum fuse_dax_mode mode,
1298 struct dax_device *dax_dev);
1299 void fuse_dax_conn_free(struct fuse_conn *fc);
1300 bool fuse_dax_inode_alloc(struct super_block *sb, struct fuse_inode *fi);
1301 void fuse_dax_inode_init(struct inode *inode, unsigned int flags);
1302 void fuse_dax_inode_cleanup(struct inode *inode);
1303 void fuse_dax_dontcache(struct inode *inode, unsigned int flags);
1304 bool fuse_dax_check_alignment(struct fuse_conn *fc, unsigned int map_alignment);
1305 void fuse_dax_cancel_work(struct fuse_conn *fc);
1306
1307 /* ioctl.c */
1308 long fuse_file_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
1309 long fuse_file_compat_ioctl(struct file *file, unsigned int cmd,
1310 unsigned long arg);
1311 int fuse_fileattr_get(struct dentry *dentry, struct fileattr *fa);
1312 int fuse_fileattr_set(struct user_namespace *mnt_userns,
1313 struct dentry *dentry, struct fileattr *fa);
1314
1315 /* file.c */
1316
1317 struct fuse_file *fuse_file_open(struct fuse_mount *fm, u64 nodeid,
1318 unsigned int open_flags, bool isdir);
1319 void fuse_file_release(struct inode *inode, struct fuse_file *ff,
1320 unsigned int open_flags, fl_owner_t id, bool isdir);
1321
1322 #endif /* _FS_FUSE_I_H */
1323
