2 FUSE: Filesystem in Userspace
3 Copyright (C) 2001-2008 Miklos Szeredi <miklos@szeredi.hu>
5 This program can be distributed under the terms of the GNU GPL.
13 # define pr_fmt(fmt) "fuse: " fmt
16 #include <linux/fuse.h>
18 #include <linux/mount.h>
19 #include <linux/wait.h>
20 #include <linux/list.h>
21 #include <linux/spinlock.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>
35 /** Default max number of pages that can be used in a single read request */
36 #define FUSE_DEFAULT_MAX_PAGES_PER_REQ 32
38 /** Maximum of max_pages received in init_out */
39 #define FUSE_MAX_MAX_PAGES 256
41 /** Bias for fi->writectr, meaning new writepages must not be sent */
42 #define FUSE_NOWRITE INT_MIN
44 /** It could be as large as PATH_MAX, but would that have any uses? */
45 #define FUSE_NAME_MAX 1024
47 /** Number of dentries for each connection in the control filesystem */
48 #define FUSE_CTL_NUM_DENTRIES 5
50 /** List of active connections */
51 extern struct list_head fuse_conn_list;
53 /** Global mutex protecting fuse_conn_list and the control filesystem */
54 extern struct mutex fuse_mutex;
56 /** Module parameters */
57 extern unsigned max_user_bgreq;
58 extern unsigned max_user_congthresh;
60 /* One forget request */
61 struct fuse_forget_link {
62 struct fuse_forget_one forget_one;
63 struct fuse_forget_link *next;
71 /** Unique ID, which identifies the inode between userspace
75 /** Number of lookups on this inode */
78 /** The request used for sending the FORGET message */
79 struct fuse_forget_link *forget;
81 /** Time in jiffies until the file attributes are valid */
84 /* Which attributes are invalid */
87 /** The sticky bit in inode->i_mode may have been removed, so
88 preserve the original mode */
91 /** 64 bit inode number */
94 /** Version of last attribute change */
98 /* Write related fields (regular file only) */
100 /* Files usable in writepage. Protected by fi->lock */
101 struct list_head write_files;
103 /* Writepages pending on truncate or fsync */
104 struct list_head queued_writes;
106 /* Number of sent writes, a negative bias
107 * (FUSE_NOWRITE) means more writes are blocked */
110 /* Waitq for writepage completion */
111 wait_queue_head_t page_waitq;
113 /* List of writepage requestst (pending or sent) */
114 struct rb_root writepages;
117 /* readdir cache (directory only) */
119 /* true if fully cached */
125 /* position at end of cache (position of next entry) */
128 /* version of the cache */
131 /* modification time of directory when cache was
133 struct timespec64 mtime;
135 /* iversion of directory when cache was started */
138 /* protects above fields */
143 /** Miscellaneous bits describing inode state */
146 /** Lock for serializing lookup and readdir for back compatibility*/
149 /** Lock to protect write related fields */
153 * Can't take inode lock in fault path (leads to circular dependency).
154 * Introduce another semaphore which can be taken in fault path and
155 * then other filesystem paths can take this to block faults.
157 struct rw_semaphore i_mmap_sem;
159 #ifdef CONFIG_FUSE_DAX
161 * Dax specific inode data
163 struct fuse_inode_dax *dax;
167 /** FUSE inode state bits */
169 /** Advise readdirplus */
170 FUSE_I_ADVISE_RDPLUS,
171 /** Initialized with readdirplus */
173 /** An operation changing file size is in progress */
174 FUSE_I_SIZE_UNSTABLE,
181 struct fuse_release_args;
183 /** FUSE specific file data */
185 /** Fuse connection for this file */
186 struct fuse_mount *fm;
188 /* Argument space reserved for release */
189 struct fuse_release_args *release_args;
191 /** Kernel file handle guaranteed to be unique */
194 /** File handle used by userspace */
197 /** Node id of this file */
203 /** FOPEN_* flags returned by open */
206 /** Entry on inode's write_files list */
207 struct list_head write_entry;
209 /* Readdir related */
212 * Protects below fields against (crazy) parallel readdir on
213 * same open file. Uncontended in the normal case.
217 /* Dir stream position */
220 /* Offset in cache */
223 /* Version of cache we are reading */
228 /** RB node to be linked on fuse_conn->polled_files */
229 struct rb_node polled_node;
231 /** Wait queue head for poll */
232 wait_queue_head_t poll_wait;
234 /** Has flock been performed on this file? */
238 /** One input argument of a request */
244 /** One output argument of a request */
250 /** FUSE page descriptor */
251 struct fuse_page_desc {
259 unsigned short in_numargs;
260 unsigned short out_numargs;
270 struct fuse_in_arg in_args[3];
271 struct fuse_arg out_args[2];
272 void (*end)(struct fuse_mount *fm, struct fuse_args *args, int error);
275 struct fuse_args_pages {
276 struct fuse_args args;
278 struct fuse_page_desc *descs;
279 unsigned int num_pages;
282 #define FUSE_ARGS(args) struct fuse_args args = {}
284 /** The request IO state (for asynchronous processing) */
285 struct fuse_io_priv {
297 struct completion *done;
301 #define FUSE_IO_PRIV_SYNC(i) \
303 .refcnt = KREF_INIT(1), \
311 * FR_ISREPLY: set if the request has reply
312 * FR_FORCE: force sending of the request even if interrupted
313 * FR_BACKGROUND: request is sent in the background
314 * FR_WAITING: request is counted as "waiting"
315 * FR_ABORTED: the request was aborted
316 * FR_INTERRUPTED: the request has been interrupted
317 * FR_LOCKED: data is being copied to/from the request
318 * FR_PENDING: request is not yet in userspace
319 * FR_SENT: request is in userspace, waiting for an answer
320 * FR_FINISHED: request is finished
321 * FR_PRIVATE: request is on private list
322 * FR_ASYNC: request is asynchronous
340 * A request to the client
342 * .waitq.lock protects the following fields:
344 * - FR_LOCKED (may also be modified under fc->lock, tested under both)
347 /** This can be on either pending processing or io lists in
349 struct list_head list;
351 /** Entry on the interrupts list */
352 struct list_head intr_entry;
354 /* Input/output arguments */
355 struct fuse_args *args;
360 /* Request flags, updated with test/set/clear_bit() */
363 /* The request input header */
365 struct fuse_in_header h;
368 /* The request output header */
370 struct fuse_out_header h;
373 /** Used to wake up the task waiting for completion of request*/
374 wait_queue_head_t waitq;
376 #if IS_ENABLED(CONFIG_VIRTIO_FS)
377 /** virtio-fs's physically contiguous buffer for in and out args */
381 /** fuse_mount this request belongs to */
382 struct fuse_mount *fm;
388 * Input queue callbacks
390 * Input queue signalling is device-specific. For example, the /dev/fuse file
391 * uses fiq->waitq and fasync to wake processes that are waiting on queue
392 * readiness. These callbacks allow other device types to respond to input
395 struct fuse_iqueue_ops {
397 * Signal that a forget has been queued
399 void (*wake_forget_and_unlock)(struct fuse_iqueue *fiq)
400 __releases(fiq->lock);
403 * Signal that an INTERRUPT request has been queued
405 void (*wake_interrupt_and_unlock)(struct fuse_iqueue *fiq)
406 __releases(fiq->lock);
409 * Signal that a request has been queued
411 void (*wake_pending_and_unlock)(struct fuse_iqueue *fiq)
412 __releases(fiq->lock);
415 * Clean up when fuse_iqueue is destroyed
417 void (*release)(struct fuse_iqueue *fiq);
420 /** /dev/fuse input queue operations */
421 extern const struct fuse_iqueue_ops fuse_dev_fiq_ops;
424 /** Connection established */
427 /** Lock protecting accesses to members of this structure */
430 /** Readers of the connection are waiting on this */
431 wait_queue_head_t waitq;
433 /** The next unique request id */
436 /** The list of pending requests */
437 struct list_head pending;
439 /** Pending interrupts */
440 struct list_head interrupts;
442 /** Queue of pending forgets */
443 struct fuse_forget_link forget_list_head;
444 struct fuse_forget_link *forget_list_tail;
446 /** Batching of FORGET requests (positive indicates FORGET batch) */
449 /** O_ASYNC requests */
450 struct fasync_struct *fasync;
452 /** Device-specific callbacks */
453 const struct fuse_iqueue_ops *ops;
455 /** Device-specific state */
459 #define FUSE_PQ_HASH_BITS 8
460 #define FUSE_PQ_HASH_SIZE (1 << FUSE_PQ_HASH_BITS)
463 /** Connection established */
466 /** Lock protecting accessess to members of this structure */
469 /** Hash table of requests being processed */
470 struct list_head *processing;
472 /** The list of requests under I/O */
477 * Fuse device instance
480 /** Fuse connection for this device */
481 struct fuse_conn *fc;
483 /** Processing queue */
484 struct fuse_pqueue pq;
486 /** list entry on fc->devices */
487 struct list_head entry;
490 struct fuse_fs_context {
493 unsigned int rootmode;
498 bool rootmode_present:1;
499 bool user_id_present:1;
500 bool group_id_present:1;
501 bool default_permissions:1;
505 bool no_force_umount:1;
506 bool legacy_opts_show:1;
508 unsigned int max_read;
509 unsigned int blksize;
512 /* DAX device, may be NULL */
513 struct dax_device *dax_dev;
515 /* fuse_dev pointer to fill in, should contain NULL on entry */
519 struct fuse_sync_bucket {
520 /* count is a possible scalability bottleneck */
522 wait_queue_head_t waitq;
529 * This structure is created, when the root filesystem is mounted, and
530 * is destroyed, when the client device is closed and the last
531 * fuse_mount is destroyed.
534 /** Lock protecting accessess to members of this structure */
540 /** Number of fuse_dev's */
545 /** The user id for this mount */
548 /** The group id for this mount */
551 /** The pid namespace for this mount */
552 struct pid_namespace *pid_ns;
554 /** The user namespace for this mount */
555 struct user_namespace *user_ns;
557 /** Maximum read size */
560 /** Maximum write size */
563 /** Maximum number of pages that can be used in a single request */
564 unsigned int max_pages;
566 /** Constrain ->max_pages to this value during feature negotiation */
567 unsigned int max_pages_limit;
570 struct fuse_iqueue iq;
572 /** The next unique kernel file handle */
575 /** rbtree of fuse_files waiting for poll events indexed by ph */
576 struct rb_root polled_files;
578 /** Maximum number of outstanding background requests */
579 unsigned max_background;
581 /** Number of background requests at which congestion starts */
582 unsigned congestion_threshold;
584 /** Number of requests currently in the background */
585 unsigned num_background;
587 /** Number of background requests currently queued for userspace */
588 unsigned active_background;
590 /** The list of background requests set aside for later queuing */
591 struct list_head bg_queue;
593 /** Protects: max_background, congestion_threshold, num_background,
594 * active_background, bg_queue, blocked */
597 /** Flag indicating that INIT reply has been received. Allocating
598 * any fuse request will be suspended until the flag is set */
601 /** Flag indicating if connection is blocked. This will be
602 the case before the INIT reply is received, and if there
603 are too many outstading backgrounds requests */
606 /** waitq for blocked connection */
607 wait_queue_head_t blocked_waitq;
609 /** Connection established, cleared on umount, connection
610 abort and device release */
613 /** Connection aborted via sysfs */
616 /** Connection failed (version mismatch). Cannot race with
617 setting other bitfields since it is only set once in INIT
618 reply, before any other request, and never cleared */
619 unsigned conn_error:1;
621 /** Connection successful. Only set in INIT */
622 unsigned conn_init:1;
624 /** Do readpages asynchronously? Only set in INIT */
625 unsigned async_read:1;
627 /** Return an unique read error after abort. Only set in INIT */
628 unsigned abort_err:1;
630 /** Do not send separate SETATTR request before open(O_TRUNC) */
631 unsigned atomic_o_trunc:1;
633 /** Filesystem supports NFS exporting. Only set in INIT */
634 unsigned export_support:1;
636 /** write-back cache policy (default is write-through) */
637 unsigned writeback_cache:1;
639 /** allow parallel lookups and readdir (default is serialized) */
640 unsigned parallel_dirops:1;
642 /** handle fs handles killing suid/sgid/cap on write/chown/trunc */
643 unsigned handle_killpriv:1;
645 /** cache READLINK responses in page cache */
646 unsigned cache_symlinks:1;
648 /* show legacy mount options */
649 unsigned int legacy_opts_show:1;
652 * fs kills suid/sgid/cap on write/chown/trunc. suid is killed on
653 * write/trunc only if caller did not have CAP_FSETID. sgid is killed
654 * on write/truncate only if caller did not have CAP_FSETID as well as
655 * file has group execute permission.
657 unsigned handle_killpriv_v2:1;
660 * The following bitfields are only for optimization purposes
661 * and hence races in setting them will not cause malfunction
664 /** Is open/release not implemented by fs? */
667 /** Is opendir/releasedir not implemented by fs? */
668 unsigned no_opendir:1;
670 /** Is fsync not implemented by fs? */
673 /** Is fsyncdir not implemented by fs? */
674 unsigned no_fsyncdir:1;
676 /** Is flush not implemented by fs? */
679 /** Is setxattr not implemented by fs? */
680 unsigned no_setxattr:1;
682 /** Does file server support extended setxattr */
683 unsigned setxattr_ext:1;
685 /** Is getxattr not implemented by fs? */
686 unsigned no_getxattr:1;
688 /** Is listxattr not implemented by fs? */
689 unsigned no_listxattr:1;
691 /** Is removexattr not implemented by fs? */
692 unsigned no_removexattr:1;
694 /** Are posix file locking primitives not implemented by fs? */
697 /** Is access not implemented by fs? */
698 unsigned no_access:1;
700 /** Is create not implemented by fs? */
701 unsigned no_create:1;
703 /** Is interrupt not implemented by fs? */
704 unsigned no_interrupt:1;
706 /** Is bmap not implemented by fs? */
709 /** Is poll not implemented by fs? */
712 /** Do multi-page cached writes */
713 unsigned big_writes:1;
715 /** Don't apply umask to creation modes */
716 unsigned dont_mask:1;
718 /** Are BSD file locking primitives not implemented by fs? */
721 /** Is fallocate not implemented by fs? */
722 unsigned no_fallocate:1;
724 /** Is rename with flags implemented by fs? */
725 unsigned no_rename2:1;
727 /** Use enhanced/automatic page cache invalidation. */
728 unsigned auto_inval_data:1;
730 /** Filesystem is fully responsible for page cache invalidation. */
731 unsigned explicit_inval_data:1;
733 /** Does the filesystem support readdirplus? */
734 unsigned do_readdirplus:1;
736 /** Does the filesystem want adaptive readdirplus? */
737 unsigned readdirplus_auto:1;
739 /** Does the filesystem support asynchronous direct-IO submission? */
740 unsigned async_dio:1;
742 /** Is lseek not implemented by fs? */
745 /** Does the filesystem support posix acls? */
746 unsigned posix_acl:1;
748 /** Check permissions based on the file mode or not? */
749 unsigned default_permissions:1;
751 /** Allow other than the mounter user to access the filesystem ? */
752 unsigned allow_other:1;
754 /** Does the filesystem support copy_file_range? */
755 unsigned no_copy_file_range:1;
757 /* Send DESTROY request */
758 unsigned int destroy:1;
760 /* Delete dentries that have gone stale */
761 unsigned int delete_stale:1;
763 /** Do not create entry in fusectl fs */
764 unsigned int no_control:1;
766 /** Do not allow MNT_FORCE umount */
767 unsigned int no_force_umount:1;
769 /* Auto-mount submounts announced by the server */
770 unsigned int auto_submounts:1;
772 /* Propagate syncfs() to server */
773 unsigned int sync_fs:1;
775 /** The number of requests waiting for completion */
776 atomic_t num_waiting;
778 /** Negotiated minor version */
781 /** Entry on the fuse_mount_list */
782 struct list_head entry;
784 /** Device ID from the root super block */
787 /** Dentries in the control filesystem */
788 struct dentry *ctl_dentry[FUSE_CTL_NUM_DENTRIES];
790 /** number of dentries used in the above array */
793 /** Key for lock owner ID scrambling */
796 /** Version counter for attribute changes */
797 atomic64_t attr_version;
799 /** Called on final put */
800 void (*release)(struct fuse_conn *);
803 * Read/write semaphore to hold when accessing the sb of any
804 * fuse_mount belonging to this connection
806 struct rw_semaphore killsb;
808 /** List of device instances belonging to this connection */
809 struct list_head devices;
811 #ifdef CONFIG_FUSE_DAX
812 /* Dax specific conn data, non-NULL if DAX is enabled */
813 struct fuse_conn_dax *dax;
816 /** List of filesystems using this connection */
817 struct list_head mounts;
819 /* New writepages go into this bucket */
820 struct fuse_sync_bucket __rcu *curr_bucket;
824 * Represents a mounted filesystem, potentially a submount.
826 * This object allows sharing a fuse_conn between separate mounts to
827 * allow submounts with dedicated superblocks and thus separate device
831 /* Underlying (potentially shared) connection to the FUSE server */
832 struct fuse_conn *fc;
835 * Super block for this connection (fc->killsb must be held when
838 struct super_block *sb;
840 /* Entry on fc->mounts */
841 struct list_head fc_entry;
844 static inline struct fuse_mount *get_fuse_mount_super(struct super_block *sb)
846 return sb->s_fs_info;
849 static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
851 return get_fuse_mount_super(sb)->fc;
854 static inline struct fuse_mount *get_fuse_mount(struct inode *inode)
856 return get_fuse_mount_super(inode->i_sb);
859 static inline struct fuse_conn *get_fuse_conn(struct inode *inode)
861 return get_fuse_mount_super(inode->i_sb)->fc;
864 static inline struct fuse_inode *get_fuse_inode(struct inode *inode)
866 return container_of(inode, struct fuse_inode, inode);
869 static inline u64 get_node_id(struct inode *inode)
871 return get_fuse_inode(inode)->nodeid;
874 static inline int invalid_nodeid(u64 nodeid)
876 return !nodeid || nodeid == FUSE_ROOT_ID;
879 static inline u64 fuse_get_attr_version(struct fuse_conn *fc)
881 return atomic64_read(&fc->attr_version);
884 static inline bool fuse_stale_inode(const struct inode *inode, int generation,
885 struct fuse_attr *attr)
887 return inode->i_generation != generation ||
888 inode_wrong_type(inode, attr->mode);
891 static inline void fuse_make_bad(struct inode *inode)
893 remove_inode_hash(inode);
894 set_bit(FUSE_I_BAD, &get_fuse_inode(inode)->state);
897 static inline bool fuse_is_bad(struct inode *inode)
899 return unlikely(test_bit(FUSE_I_BAD, &get_fuse_inode(inode)->state));
902 static inline struct page **fuse_pages_alloc(unsigned int npages, gfp_t flags,
903 struct fuse_page_desc **desc)
907 pages = kzalloc(npages * (sizeof(struct page *) +
908 sizeof(struct fuse_page_desc)), flags);
909 *desc = (void *) (pages + npages);
914 static inline void fuse_page_descs_length_init(struct fuse_page_desc *descs,
916 unsigned int nr_pages)
920 for (i = index; i < index + nr_pages; i++)
921 descs[i].length = PAGE_SIZE - descs[i].offset;
924 static inline void fuse_sync_bucket_dec(struct fuse_sync_bucket *bucket)
926 /* Need RCU protection to prevent use after free after the decrement */
928 if (atomic_dec_and_test(&bucket->count))
929 wake_up(&bucket->waitq);
933 /** Device operations */
934 extern const struct file_operations fuse_dev_operations;
936 extern const struct dentry_operations fuse_dentry_operations;
937 extern const struct dentry_operations fuse_root_dentry_operations;
940 * Get a filled in inode
942 struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
943 int generation, struct fuse_attr *attr,
944 u64 attr_valid, u64 attr_version);
946 int fuse_lookup_name(struct super_block *sb, u64 nodeid, const struct qstr *name,
947 struct fuse_entry_out *outarg, struct inode **inode);
950 * Send FORGET command
952 void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget,
953 u64 nodeid, u64 nlookup);
955 struct fuse_forget_link *fuse_alloc_forget(void);
957 struct fuse_forget_link *fuse_dequeue_forget(struct fuse_iqueue *fiq,
959 unsigned int *countp);
962 * Initialize READ or READDIR request
964 struct fuse_io_args {
967 struct fuse_read_in in;
971 struct fuse_write_in in;
972 struct fuse_write_out out;
976 struct fuse_args_pages ap;
977 struct fuse_io_priv *io;
978 struct fuse_file *ff;
981 void fuse_read_args_fill(struct fuse_io_args *ia, struct file *file, loff_t pos,
982 size_t count, int opcode);
986 * Send OPEN or OPENDIR request
988 int fuse_open_common(struct inode *inode, struct file *file, bool isdir);
990 struct fuse_file *fuse_file_alloc(struct fuse_mount *fm);
991 void fuse_file_free(struct fuse_file *ff);
992 void fuse_finish_open(struct inode *inode, struct file *file);
994 void fuse_sync_release(struct fuse_inode *fi, struct fuse_file *ff,
998 * Send RELEASE or RELEASEDIR request
1000 void fuse_release_common(struct file *file, bool isdir);
1003 * Send FSYNC or FSYNCDIR request
1005 int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
1006 int datasync, int opcode);
1009 * Notify poll wakeup
1011 int fuse_notify_poll_wakeup(struct fuse_conn *fc,
1012 struct fuse_notify_poll_wakeup_out *outarg);
1015 * Initialize file operations on a regular file
1017 void fuse_init_file_inode(struct inode *inode);
1020 * Initialize inode operations on regular files and special files
1022 void fuse_init_common(struct inode *inode);
1025 * Initialize inode and file operations on a directory
1027 void fuse_init_dir(struct inode *inode);
1030 * Initialize inode operations on a symlink
1032 void fuse_init_symlink(struct inode *inode);
1035 * Change attributes of an inode
1037 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
1038 u64 attr_valid, u64 attr_version);
1040 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
1044 * Initialize the client device
1046 int fuse_dev_init(void);
1049 * Cleanup the client device
1051 void fuse_dev_cleanup(void);
1053 int fuse_ctl_init(void);
1054 void __exit fuse_ctl_cleanup(void);
1057 * Simple request sending that does request allocation and freeing
1059 ssize_t fuse_simple_request(struct fuse_mount *fm, struct fuse_args *args);
1060 int fuse_simple_background(struct fuse_mount *fm, struct fuse_args *args,
1064 * End a finished request
1066 void fuse_request_end(struct fuse_req *req);
1068 /* Abort all requests */
1069 void fuse_abort_conn(struct fuse_conn *fc);
1070 void fuse_wait_aborted(struct fuse_conn *fc);
1073 * Invalidate inode attributes
1075 void fuse_invalidate_attr(struct inode *inode);
1077 void fuse_invalidate_entry_cache(struct dentry *entry);
1079 void fuse_invalidate_atime(struct inode *inode);
1081 u64 entry_attr_timeout(struct fuse_entry_out *o);
1082 void fuse_change_entry_timeout(struct dentry *entry, struct fuse_entry_out *o);
1085 * Acquire reference to fuse_conn
1087 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc);
1090 * Initialize fuse_conn
1092 void fuse_conn_init(struct fuse_conn *fc, struct fuse_mount *fm,
1093 struct user_namespace *user_ns,
1094 const struct fuse_iqueue_ops *fiq_ops, void *fiq_priv);
1097 * Release reference to fuse_conn
1099 void fuse_conn_put(struct fuse_conn *fc);
1101 struct fuse_dev *fuse_dev_alloc_install(struct fuse_conn *fc);
1102 struct fuse_dev *fuse_dev_alloc(void);
1103 void fuse_dev_install(struct fuse_dev *fud, struct fuse_conn *fc);
1104 void fuse_dev_free(struct fuse_dev *fud);
1105 void fuse_send_init(struct fuse_mount *fm);
1108 * Fill in superblock and initialize fuse connection
1109 * @sb: partially-initialized superblock to fill in
1110 * @ctx: mount context
1112 int fuse_fill_super_common(struct super_block *sb, struct fuse_fs_context *ctx);
1115 * Remove the mount from the connection
1117 * Returns whether this was the last mount
1119 bool fuse_mount_remove(struct fuse_mount *fm);
1122 * Setup context ops for submounts
1124 int fuse_init_fs_context_submount(struct fs_context *fsc);
1127 * Shut down the connection (possibly sending DESTROY request).
1129 void fuse_conn_destroy(struct fuse_mount *fm);
1132 * Add connection to control filesystem
1134 int fuse_ctl_add_conn(struct fuse_conn *fc);
1137 * Remove connection from control filesystem
1139 void fuse_ctl_remove_conn(struct fuse_conn *fc);
1142 * Is file type valid?
1144 int fuse_valid_type(int m);
1146 bool fuse_invalid_attr(struct fuse_attr *attr);
1149 * Is current process allowed to perform filesystem operation?
1151 int fuse_allow_current_process(struct fuse_conn *fc);
1153 u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id);
1155 void fuse_update_ctime(struct inode *inode);
1157 int fuse_update_attributes(struct inode *inode, struct file *file);
1159 void fuse_flush_writepages(struct inode *inode);
1161 void fuse_set_nowrite(struct inode *inode);
1162 void fuse_release_nowrite(struct inode *inode);
1165 * Scan all fuse_mounts belonging to fc to find the first where
1166 * ilookup5() returns a result. Return that result and the
1167 * respective fuse_mount in *fm (unless fm is NULL).
1169 * The caller must hold fc->killsb.
1171 struct inode *fuse_ilookup(struct fuse_conn *fc, u64 nodeid,
1172 struct fuse_mount **fm);
1175 * File-system tells the kernel to invalidate cache for the given node id.
1177 int fuse_reverse_inval_inode(struct fuse_conn *fc, u64 nodeid,
1178 loff_t offset, loff_t len);
1181 * File-system tells the kernel to invalidate parent attributes and
1182 * the dentry matching parent/name.
1184 * If the child_nodeid is non-zero and:
1185 * - matches the inode number for the dentry matching parent/name,
1186 * - is not a mount point
1187 * - is a file or oan empty directory
1188 * then the dentry is unhashed (d_delete()).
1190 int fuse_reverse_inval_entry(struct fuse_conn *fc, u64 parent_nodeid,
1191 u64 child_nodeid, struct qstr *name);
1193 int fuse_do_open(struct fuse_mount *fm, u64 nodeid, struct file *file,
1197 * fuse_direct_io() flags
1200 /** If set, it is WRITE; otherwise - READ */
1201 #define FUSE_DIO_WRITE (1 << 0)
1203 /** CUSE pass fuse_direct_io() a file which f_mapping->host is not from FUSE */
1204 #define FUSE_DIO_CUSE (1 << 1)
1206 ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter,
1207 loff_t *ppos, int flags);
1208 long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
1209 unsigned int flags);
1210 long fuse_ioctl_common(struct file *file, unsigned int cmd,
1211 unsigned long arg, unsigned int flags);
1212 __poll_t fuse_file_poll(struct file *file, poll_table *wait);
1213 int fuse_dev_release(struct inode *inode, struct file *file);
1215 bool fuse_write_update_size(struct inode *inode, loff_t pos);
1217 int fuse_flush_times(struct inode *inode, struct fuse_file *ff);
1218 int fuse_write_inode(struct inode *inode, struct writeback_control *wbc);
1220 int fuse_do_setattr(struct dentry *dentry, struct iattr *attr,
1223 void fuse_set_initialized(struct fuse_conn *fc);
1225 void fuse_unlock_inode(struct inode *inode, bool locked);
1226 bool fuse_lock_inode(struct inode *inode);
1228 int fuse_setxattr(struct inode *inode, const char *name, const void *value,
1229 size_t size, int flags, unsigned int extra_flags);
1230 ssize_t fuse_getxattr(struct inode *inode, const char *name, void *value,
1232 ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size);
1233 int fuse_removexattr(struct inode *inode, const char *name);
1234 extern const struct xattr_handler *fuse_xattr_handlers[];
1235 extern const struct xattr_handler *fuse_acl_xattr_handlers[];
1236 extern const struct xattr_handler *fuse_no_acl_xattr_handlers[];
1239 struct posix_acl *fuse_get_acl(struct inode *inode, int type);
1240 int fuse_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
1241 struct posix_acl *acl, int type);
1244 int fuse_readdir(struct file *file, struct dir_context *ctx);
1247 * Return the number of bytes in an arguments list
1249 unsigned int fuse_len_args(unsigned int numargs, struct fuse_arg *args);
1252 * Get the next unique ID for a request
1254 u64 fuse_get_unique(struct fuse_iqueue *fiq);
1255 void fuse_free_conn(struct fuse_conn *fc);
1259 #define FUSE_IS_DAX(inode) (IS_ENABLED(CONFIG_FUSE_DAX) && IS_DAX(inode))
1261 ssize_t fuse_dax_read_iter(struct kiocb *iocb, struct iov_iter *to);
1262 ssize_t fuse_dax_write_iter(struct kiocb *iocb, struct iov_iter *from);
1263 int fuse_dax_mmap(struct file *file, struct vm_area_struct *vma);
1264 int fuse_dax_break_layouts(struct inode *inode, u64 dmap_start, u64 dmap_end);
1265 int fuse_dax_conn_alloc(struct fuse_conn *fc, struct dax_device *dax_dev);
1266 void fuse_dax_conn_free(struct fuse_conn *fc);
1267 bool fuse_dax_inode_alloc(struct super_block *sb, struct fuse_inode *fi);
1268 void fuse_dax_inode_init(struct inode *inode);
1269 void fuse_dax_inode_cleanup(struct inode *inode);
1270 bool fuse_dax_check_alignment(struct fuse_conn *fc, unsigned int map_alignment);
1271 void fuse_dax_cancel_work(struct fuse_conn *fc);
1274 long fuse_file_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
1275 long fuse_file_compat_ioctl(struct file *file, unsigned int cmd,
1277 int fuse_fileattr_get(struct dentry *dentry, struct fileattr *fa);
1278 int fuse_fileattr_set(struct user_namespace *mnt_userns,
1279 struct dentry *dentry, struct fileattr *fa);
1283 struct fuse_file *fuse_file_open(struct fuse_mount *fm, u64 nodeid,
1284 unsigned int open_flags, bool isdir);
1285 void fuse_file_release(struct inode *inode, struct fuse_file *ff,
1286 unsigned int open_flags, fl_owner_t id, bool isdir);
1288 #endif /* _FS_FUSE_I_H */