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 */
152 #ifdef CONFIG_FUSE_DAX
154 * Dax specific inode data
156 struct fuse_inode_dax *dax;
160 /** FUSE inode state bits */
162 /** Advise readdirplus */
163 FUSE_I_ADVISE_RDPLUS,
164 /** Initialized with readdirplus */
166 /** An operation changing file size is in progress */
167 FUSE_I_SIZE_UNSTABLE,
174 struct fuse_release_args;
176 /** FUSE specific file data */
178 /** Fuse connection for this file */
179 struct fuse_mount *fm;
181 /* Argument space reserved for release */
182 struct fuse_release_args *release_args;
184 /** Kernel file handle guaranteed to be unique */
187 /** File handle used by userspace */
190 /** Node id of this file */
196 /** FOPEN_* flags returned by open */
199 /** Entry on inode's write_files list */
200 struct list_head write_entry;
202 /* Readdir related */
205 * Protects below fields against (crazy) parallel readdir on
206 * same open file. Uncontended in the normal case.
210 /* Dir stream position */
213 /* Offset in cache */
216 /* Version of cache we are reading */
221 /** RB node to be linked on fuse_conn->polled_files */
222 struct rb_node polled_node;
224 /** Wait queue head for poll */
225 wait_queue_head_t poll_wait;
227 /** Has flock been performed on this file? */
231 /** One input argument of a request */
237 /** One output argument of a request */
243 /** FUSE page descriptor */
244 struct fuse_page_desc {
252 unsigned short in_numargs;
253 unsigned short out_numargs;
263 struct fuse_in_arg in_args[3];
264 struct fuse_arg out_args[2];
265 void (*end)(struct fuse_mount *fm, struct fuse_args *args, int error);
268 struct fuse_args_pages {
269 struct fuse_args args;
271 struct fuse_page_desc *descs;
272 unsigned int num_pages;
275 #define FUSE_ARGS(args) struct fuse_args args = {}
277 /** The request IO state (for asynchronous processing) */
278 struct fuse_io_priv {
290 struct completion *done;
294 #define FUSE_IO_PRIV_SYNC(i) \
296 .refcnt = KREF_INIT(1), \
304 * FR_ISREPLY: set if the request has reply
305 * FR_FORCE: force sending of the request even if interrupted
306 * FR_BACKGROUND: request is sent in the background
307 * FR_WAITING: request is counted as "waiting"
308 * FR_ABORTED: the request was aborted
309 * FR_INTERRUPTED: the request has been interrupted
310 * FR_LOCKED: data is being copied to/from the request
311 * FR_PENDING: request is not yet in userspace
312 * FR_SENT: request is in userspace, waiting for an answer
313 * FR_FINISHED: request is finished
314 * FR_PRIVATE: request is on private list
315 * FR_ASYNC: request is asynchronous
333 * A request to the client
335 * .waitq.lock protects the following fields:
337 * - FR_LOCKED (may also be modified under fc->lock, tested under both)
340 /** This can be on either pending processing or io lists in
342 struct list_head list;
344 /** Entry on the interrupts list */
345 struct list_head intr_entry;
347 /* Input/output arguments */
348 struct fuse_args *args;
353 /* Request flags, updated with test/set/clear_bit() */
356 /* The request input header */
358 struct fuse_in_header h;
361 /* The request output header */
363 struct fuse_out_header h;
366 /** Used to wake up the task waiting for completion of request*/
367 wait_queue_head_t waitq;
369 #if IS_ENABLED(CONFIG_VIRTIO_FS)
370 /** virtio-fs's physically contiguous buffer for in and out args */
374 /** fuse_mount this request belongs to */
375 struct fuse_mount *fm;
381 * Input queue callbacks
383 * Input queue signalling is device-specific. For example, the /dev/fuse file
384 * uses fiq->waitq and fasync to wake processes that are waiting on queue
385 * readiness. These callbacks allow other device types to respond to input
388 struct fuse_iqueue_ops {
390 * Signal that a forget has been queued
392 void (*wake_forget_and_unlock)(struct fuse_iqueue *fiq)
393 __releases(fiq->lock);
396 * Signal that an INTERRUPT request has been queued
398 void (*wake_interrupt_and_unlock)(struct fuse_iqueue *fiq)
399 __releases(fiq->lock);
402 * Signal that a request has been queued
404 void (*wake_pending_and_unlock)(struct fuse_iqueue *fiq)
405 __releases(fiq->lock);
408 * Clean up when fuse_iqueue is destroyed
410 void (*release)(struct fuse_iqueue *fiq);
413 /** /dev/fuse input queue operations */
414 extern const struct fuse_iqueue_ops fuse_dev_fiq_ops;
417 /** Connection established */
420 /** Lock protecting accesses to members of this structure */
423 /** Readers of the connection are waiting on this */
424 wait_queue_head_t waitq;
426 /** The next unique request id */
429 /** The list of pending requests */
430 struct list_head pending;
432 /** Pending interrupts */
433 struct list_head interrupts;
435 /** Queue of pending forgets */
436 struct fuse_forget_link forget_list_head;
437 struct fuse_forget_link *forget_list_tail;
439 /** Batching of FORGET requests (positive indicates FORGET batch) */
442 /** O_ASYNC requests */
443 struct fasync_struct *fasync;
445 /** Device-specific callbacks */
446 const struct fuse_iqueue_ops *ops;
448 /** Device-specific state */
452 #define FUSE_PQ_HASH_BITS 8
453 #define FUSE_PQ_HASH_SIZE (1 << FUSE_PQ_HASH_BITS)
456 /** Connection established */
459 /** Lock protecting accessess to members of this structure */
462 /** Hash table of requests being processed */
463 struct list_head *processing;
465 /** The list of requests under I/O */
470 * Fuse device instance
473 /** Fuse connection for this device */
474 struct fuse_conn *fc;
476 /** Processing queue */
477 struct fuse_pqueue pq;
479 /** list entry on fc->devices */
480 struct list_head entry;
483 struct fuse_fs_context {
486 unsigned int rootmode;
491 bool rootmode_present:1;
492 bool user_id_present:1;
493 bool group_id_present:1;
494 bool default_permissions:1;
498 bool no_force_umount:1;
499 bool legacy_opts_show:1;
501 unsigned int max_read;
502 unsigned int blksize;
505 /* DAX device, may be NULL */
506 struct dax_device *dax_dev;
508 /* fuse_dev pointer to fill in, should contain NULL on entry */
512 struct fuse_sync_bucket {
513 /* count is a possible scalability bottleneck */
515 wait_queue_head_t waitq;
522 * This structure is created, when the root filesystem is mounted, and
523 * is destroyed, when the client device is closed and the last
524 * fuse_mount is destroyed.
527 /** Lock protecting accessess to members of this structure */
533 /** Number of fuse_dev's */
538 /** The user id for this mount */
541 /** The group id for this mount */
544 /** The pid namespace for this mount */
545 struct pid_namespace *pid_ns;
547 /** The user namespace for this mount */
548 struct user_namespace *user_ns;
550 /** Maximum read size */
553 /** Maximum write size */
556 /** Maximum number of pages that can be used in a single request */
557 unsigned int max_pages;
559 /** Constrain ->max_pages to this value during feature negotiation */
560 unsigned int max_pages_limit;
563 struct fuse_iqueue iq;
565 /** The next unique kernel file handle */
568 /** rbtree of fuse_files waiting for poll events indexed by ph */
569 struct rb_root polled_files;
571 /** Maximum number of outstanding background requests */
572 unsigned max_background;
574 /** Number of background requests at which congestion starts */
575 unsigned congestion_threshold;
577 /** Number of requests currently in the background */
578 unsigned num_background;
580 /** Number of background requests currently queued for userspace */
581 unsigned active_background;
583 /** The list of background requests set aside for later queuing */
584 struct list_head bg_queue;
586 /** Protects: max_background, congestion_threshold, num_background,
587 * active_background, bg_queue, blocked */
590 /** Flag indicating that INIT reply has been received. Allocating
591 * any fuse request will be suspended until the flag is set */
594 /** Flag indicating if connection is blocked. This will be
595 the case before the INIT reply is received, and if there
596 are too many outstading backgrounds requests */
599 /** waitq for blocked connection */
600 wait_queue_head_t blocked_waitq;
602 /** Connection established, cleared on umount, connection
603 abort and device release */
606 /** Connection aborted via sysfs */
609 /** Connection failed (version mismatch). Cannot race with
610 setting other bitfields since it is only set once in INIT
611 reply, before any other request, and never cleared */
612 unsigned conn_error:1;
614 /** Connection successful. Only set in INIT */
615 unsigned conn_init:1;
617 /** Do readpages asynchronously? Only set in INIT */
618 unsigned async_read:1;
620 /** Return an unique read error after abort. Only set in INIT */
621 unsigned abort_err:1;
623 /** Do not send separate SETATTR request before open(O_TRUNC) */
624 unsigned atomic_o_trunc:1;
626 /** Filesystem supports NFS exporting. Only set in INIT */
627 unsigned export_support:1;
629 /** write-back cache policy (default is write-through) */
630 unsigned writeback_cache:1;
632 /** allow parallel lookups and readdir (default is serialized) */
633 unsigned parallel_dirops:1;
635 /** handle fs handles killing suid/sgid/cap on write/chown/trunc */
636 unsigned handle_killpriv:1;
638 /** cache READLINK responses in page cache */
639 unsigned cache_symlinks:1;
641 /* show legacy mount options */
642 unsigned int legacy_opts_show:1;
645 * fs kills suid/sgid/cap on write/chown/trunc. suid is killed on
646 * write/trunc only if caller did not have CAP_FSETID. sgid is killed
647 * on write/truncate only if caller did not have CAP_FSETID as well as
648 * file has group execute permission.
650 unsigned handle_killpriv_v2:1;
653 * The following bitfields are only for optimization purposes
654 * and hence races in setting them will not cause malfunction
657 /** Is open/release not implemented by fs? */
660 /** Is opendir/releasedir not implemented by fs? */
661 unsigned no_opendir:1;
663 /** Is fsync not implemented by fs? */
666 /** Is fsyncdir not implemented by fs? */
667 unsigned no_fsyncdir:1;
669 /** Is flush not implemented by fs? */
672 /** Is setxattr not implemented by fs? */
673 unsigned no_setxattr:1;
675 /** Does file server support extended setxattr */
676 unsigned setxattr_ext:1;
678 /** Is getxattr not implemented by fs? */
679 unsigned no_getxattr:1;
681 /** Is listxattr not implemented by fs? */
682 unsigned no_listxattr:1;
684 /** Is removexattr not implemented by fs? */
685 unsigned no_removexattr:1;
687 /** Are posix file locking primitives not implemented by fs? */
690 /** Is access not implemented by fs? */
691 unsigned no_access:1;
693 /** Is create not implemented by fs? */
694 unsigned no_create:1;
696 /** Is interrupt not implemented by fs? */
697 unsigned no_interrupt:1;
699 /** Is bmap not implemented by fs? */
702 /** Is poll not implemented by fs? */
705 /** Do multi-page cached writes */
706 unsigned big_writes:1;
708 /** Don't apply umask to creation modes */
709 unsigned dont_mask:1;
711 /** Are BSD file locking primitives not implemented by fs? */
714 /** Is fallocate not implemented by fs? */
715 unsigned no_fallocate:1;
717 /** Is rename with flags implemented by fs? */
718 unsigned no_rename2:1;
720 /** Use enhanced/automatic page cache invalidation. */
721 unsigned auto_inval_data:1;
723 /** Filesystem is fully responsible for page cache invalidation. */
724 unsigned explicit_inval_data:1;
726 /** Does the filesystem support readdirplus? */
727 unsigned do_readdirplus:1;
729 /** Does the filesystem want adaptive readdirplus? */
730 unsigned readdirplus_auto:1;
732 /** Does the filesystem support asynchronous direct-IO submission? */
733 unsigned async_dio:1;
735 /** Is lseek not implemented by fs? */
738 /** Does the filesystem support posix acls? */
739 unsigned posix_acl:1;
741 /** Check permissions based on the file mode or not? */
742 unsigned default_permissions:1;
744 /** Allow other than the mounter user to access the filesystem ? */
745 unsigned allow_other:1;
747 /** Does the filesystem support copy_file_range? */
748 unsigned no_copy_file_range:1;
750 /* Send DESTROY request */
751 unsigned int destroy:1;
753 /* Delete dentries that have gone stale */
754 unsigned int delete_stale:1;
756 /** Do not create entry in fusectl fs */
757 unsigned int no_control:1;
759 /** Do not allow MNT_FORCE umount */
760 unsigned int no_force_umount:1;
762 /* Auto-mount submounts announced by the server */
763 unsigned int auto_submounts:1;
765 /* Propagate syncfs() to server */
766 unsigned int sync_fs:1;
768 /** The number of requests waiting for completion */
769 atomic_t num_waiting;
771 /** Negotiated minor version */
774 /** Entry on the fuse_mount_list */
775 struct list_head entry;
777 /** Device ID from the root super block */
780 /** Dentries in the control filesystem */
781 struct dentry *ctl_dentry[FUSE_CTL_NUM_DENTRIES];
783 /** number of dentries used in the above array */
786 /** Key for lock owner ID scrambling */
789 /** Version counter for attribute changes */
790 atomic64_t attr_version;
792 /** Called on final put */
793 void (*release)(struct fuse_conn *);
796 * Read/write semaphore to hold when accessing the sb of any
797 * fuse_mount belonging to this connection
799 struct rw_semaphore killsb;
801 /** List of device instances belonging to this connection */
802 struct list_head devices;
804 #ifdef CONFIG_FUSE_DAX
805 /* Dax specific conn data, non-NULL if DAX is enabled */
806 struct fuse_conn_dax *dax;
809 /** List of filesystems using this connection */
810 struct list_head mounts;
812 /* New writepages go into this bucket */
813 struct fuse_sync_bucket __rcu *curr_bucket;
817 * Represents a mounted filesystem, potentially a submount.
819 * This object allows sharing a fuse_conn between separate mounts to
820 * allow submounts with dedicated superblocks and thus separate device
824 /* Underlying (potentially shared) connection to the FUSE server */
825 struct fuse_conn *fc;
828 * Super block for this connection (fc->killsb must be held when
831 struct super_block *sb;
833 /* Entry on fc->mounts */
834 struct list_head fc_entry;
837 static inline struct fuse_mount *get_fuse_mount_super(struct super_block *sb)
839 return sb->s_fs_info;
842 static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
844 return get_fuse_mount_super(sb)->fc;
847 static inline struct fuse_mount *get_fuse_mount(struct inode *inode)
849 return get_fuse_mount_super(inode->i_sb);
852 static inline struct fuse_conn *get_fuse_conn(struct inode *inode)
854 return get_fuse_mount_super(inode->i_sb)->fc;
857 static inline struct fuse_inode *get_fuse_inode(struct inode *inode)
859 return container_of(inode, struct fuse_inode, inode);
862 static inline u64 get_node_id(struct inode *inode)
864 return get_fuse_inode(inode)->nodeid;
867 static inline int invalid_nodeid(u64 nodeid)
869 return !nodeid || nodeid == FUSE_ROOT_ID;
872 static inline u64 fuse_get_attr_version(struct fuse_conn *fc)
874 return atomic64_read(&fc->attr_version);
877 static inline bool fuse_stale_inode(const struct inode *inode, int generation,
878 struct fuse_attr *attr)
880 return inode->i_generation != generation ||
881 inode_wrong_type(inode, attr->mode);
884 static inline void fuse_make_bad(struct inode *inode)
886 remove_inode_hash(inode);
887 set_bit(FUSE_I_BAD, &get_fuse_inode(inode)->state);
890 static inline bool fuse_is_bad(struct inode *inode)
892 return unlikely(test_bit(FUSE_I_BAD, &get_fuse_inode(inode)->state));
895 static inline struct page **fuse_pages_alloc(unsigned int npages, gfp_t flags,
896 struct fuse_page_desc **desc)
900 pages = kzalloc(npages * (sizeof(struct page *) +
901 sizeof(struct fuse_page_desc)), flags);
902 *desc = (void *) (pages + npages);
907 static inline void fuse_page_descs_length_init(struct fuse_page_desc *descs,
909 unsigned int nr_pages)
913 for (i = index; i < index + nr_pages; i++)
914 descs[i].length = PAGE_SIZE - descs[i].offset;
917 static inline void fuse_sync_bucket_dec(struct fuse_sync_bucket *bucket)
919 /* Need RCU protection to prevent use after free after the decrement */
921 if (atomic_dec_and_test(&bucket->count))
922 wake_up(&bucket->waitq);
926 /** Device operations */
927 extern const struct file_operations fuse_dev_operations;
929 extern const struct dentry_operations fuse_dentry_operations;
930 extern const struct dentry_operations fuse_root_dentry_operations;
933 * Get a filled in inode
935 struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
936 int generation, struct fuse_attr *attr,
937 u64 attr_valid, u64 attr_version);
939 int fuse_lookup_name(struct super_block *sb, u64 nodeid, const struct qstr *name,
940 struct fuse_entry_out *outarg, struct inode **inode);
943 * Send FORGET command
945 void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget,
946 u64 nodeid, u64 nlookup);
948 struct fuse_forget_link *fuse_alloc_forget(void);
950 struct fuse_forget_link *fuse_dequeue_forget(struct fuse_iqueue *fiq,
952 unsigned int *countp);
955 * Initialize READ or READDIR request
957 struct fuse_io_args {
960 struct fuse_read_in in;
964 struct fuse_write_in in;
965 struct fuse_write_out out;
969 struct fuse_args_pages ap;
970 struct fuse_io_priv *io;
971 struct fuse_file *ff;
974 void fuse_read_args_fill(struct fuse_io_args *ia, struct file *file, loff_t pos,
975 size_t count, int opcode);
979 * Send OPEN or OPENDIR request
981 int fuse_open_common(struct inode *inode, struct file *file, bool isdir);
983 struct fuse_file *fuse_file_alloc(struct fuse_mount *fm);
984 void fuse_file_free(struct fuse_file *ff);
985 void fuse_finish_open(struct inode *inode, struct file *file);
987 void fuse_sync_release(struct fuse_inode *fi, struct fuse_file *ff,
991 * Send RELEASE or RELEASEDIR request
993 void fuse_release_common(struct file *file, bool isdir);
996 * Send FSYNC or FSYNCDIR request
998 int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
999 int datasync, int opcode);
1002 * Notify poll wakeup
1004 int fuse_notify_poll_wakeup(struct fuse_conn *fc,
1005 struct fuse_notify_poll_wakeup_out *outarg);
1008 * Initialize file operations on a regular file
1010 void fuse_init_file_inode(struct inode *inode);
1013 * Initialize inode operations on regular files and special files
1015 void fuse_init_common(struct inode *inode);
1018 * Initialize inode and file operations on a directory
1020 void fuse_init_dir(struct inode *inode);
1023 * Initialize inode operations on a symlink
1025 void fuse_init_symlink(struct inode *inode);
1028 * Change attributes of an inode
1030 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
1031 u64 attr_valid, u64 attr_version);
1033 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
1037 * Initialize the client device
1039 int fuse_dev_init(void);
1042 * Cleanup the client device
1044 void fuse_dev_cleanup(void);
1046 int fuse_ctl_init(void);
1047 void __exit fuse_ctl_cleanup(void);
1050 * Simple request sending that does request allocation and freeing
1052 ssize_t fuse_simple_request(struct fuse_mount *fm, struct fuse_args *args);
1053 int fuse_simple_background(struct fuse_mount *fm, struct fuse_args *args,
1057 * End a finished request
1059 void fuse_request_end(struct fuse_req *req);
1061 /* Abort all requests */
1062 void fuse_abort_conn(struct fuse_conn *fc);
1063 void fuse_wait_aborted(struct fuse_conn *fc);
1066 * Invalidate inode attributes
1068 void fuse_invalidate_attr(struct inode *inode);
1070 void fuse_invalidate_entry_cache(struct dentry *entry);
1072 void fuse_invalidate_atime(struct inode *inode);
1074 u64 entry_attr_timeout(struct fuse_entry_out *o);
1075 void fuse_change_entry_timeout(struct dentry *entry, struct fuse_entry_out *o);
1078 * Acquire reference to fuse_conn
1080 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc);
1083 * Initialize fuse_conn
1085 void fuse_conn_init(struct fuse_conn *fc, struct fuse_mount *fm,
1086 struct user_namespace *user_ns,
1087 const struct fuse_iqueue_ops *fiq_ops, void *fiq_priv);
1090 * Release reference to fuse_conn
1092 void fuse_conn_put(struct fuse_conn *fc);
1094 struct fuse_dev *fuse_dev_alloc_install(struct fuse_conn *fc);
1095 struct fuse_dev *fuse_dev_alloc(void);
1096 void fuse_dev_install(struct fuse_dev *fud, struct fuse_conn *fc);
1097 void fuse_dev_free(struct fuse_dev *fud);
1098 void fuse_send_init(struct fuse_mount *fm);
1101 * Fill in superblock and initialize fuse connection
1102 * @sb: partially-initialized superblock to fill in
1103 * @ctx: mount context
1105 int fuse_fill_super_common(struct super_block *sb, struct fuse_fs_context *ctx);
1108 * Remove the mount from the connection
1110 * Returns whether this was the last mount
1112 bool fuse_mount_remove(struct fuse_mount *fm);
1115 * Setup context ops for submounts
1117 int fuse_init_fs_context_submount(struct fs_context *fsc);
1120 * Shut down the connection (possibly sending DESTROY request).
1122 void fuse_conn_destroy(struct fuse_mount *fm);
1124 /* Drop the connection and free the fuse mount */
1125 void fuse_mount_destroy(struct fuse_mount *fm);
1128 * Add connection to control filesystem
1130 int fuse_ctl_add_conn(struct fuse_conn *fc);
1133 * Remove connection from control filesystem
1135 void fuse_ctl_remove_conn(struct fuse_conn *fc);
1138 * Is file type valid?
1140 int fuse_valid_type(int m);
1142 bool fuse_invalid_attr(struct fuse_attr *attr);
1145 * Is current process allowed to perform filesystem operation?
1147 int fuse_allow_current_process(struct fuse_conn *fc);
1149 u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id);
1151 void fuse_update_ctime(struct inode *inode);
1153 int fuse_update_attributes(struct inode *inode, struct file *file);
1155 void fuse_flush_writepages(struct inode *inode);
1157 void fuse_set_nowrite(struct inode *inode);
1158 void fuse_release_nowrite(struct inode *inode);
1161 * Scan all fuse_mounts belonging to fc to find the first where
1162 * ilookup5() returns a result. Return that result and the
1163 * respective fuse_mount in *fm (unless fm is NULL).
1165 * The caller must hold fc->killsb.
1167 struct inode *fuse_ilookup(struct fuse_conn *fc, u64 nodeid,
1168 struct fuse_mount **fm);
1171 * File-system tells the kernel to invalidate cache for the given node id.
1173 int fuse_reverse_inval_inode(struct fuse_conn *fc, u64 nodeid,
1174 loff_t offset, loff_t len);
1177 * File-system tells the kernel to invalidate parent attributes and
1178 * the dentry matching parent/name.
1180 * If the child_nodeid is non-zero and:
1181 * - matches the inode number for the dentry matching parent/name,
1182 * - is not a mount point
1183 * - is a file or oan empty directory
1184 * then the dentry is unhashed (d_delete()).
1186 int fuse_reverse_inval_entry(struct fuse_conn *fc, u64 parent_nodeid,
1187 u64 child_nodeid, struct qstr *name);
1189 int fuse_do_open(struct fuse_mount *fm, u64 nodeid, struct file *file,
1193 * fuse_direct_io() flags
1196 /** If set, it is WRITE; otherwise - READ */
1197 #define FUSE_DIO_WRITE (1 << 0)
1199 /** CUSE pass fuse_direct_io() a file which f_mapping->host is not from FUSE */
1200 #define FUSE_DIO_CUSE (1 << 1)
1202 ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter,
1203 loff_t *ppos, int flags);
1204 long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
1205 unsigned int flags);
1206 long fuse_ioctl_common(struct file *file, unsigned int cmd,
1207 unsigned long arg, unsigned int flags);
1208 __poll_t fuse_file_poll(struct file *file, poll_table *wait);
1209 int fuse_dev_release(struct inode *inode, struct file *file);
1211 bool fuse_write_update_size(struct inode *inode, loff_t pos);
1213 int fuse_flush_times(struct inode *inode, struct fuse_file *ff);
1214 int fuse_write_inode(struct inode *inode, struct writeback_control *wbc);
1216 int fuse_do_setattr(struct dentry *dentry, struct iattr *attr,
1219 void fuse_set_initialized(struct fuse_conn *fc);
1221 void fuse_unlock_inode(struct inode *inode, bool locked);
1222 bool fuse_lock_inode(struct inode *inode);
1224 int fuse_setxattr(struct inode *inode, const char *name, const void *value,
1225 size_t size, int flags, unsigned int extra_flags);
1226 ssize_t fuse_getxattr(struct inode *inode, const char *name, void *value,
1228 ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size);
1229 int fuse_removexattr(struct inode *inode, const char *name);
1230 extern const struct xattr_handler *fuse_xattr_handlers[];
1231 extern const struct xattr_handler *fuse_acl_xattr_handlers[];
1232 extern const struct xattr_handler *fuse_no_acl_xattr_handlers[];
1235 struct posix_acl *fuse_get_acl(struct inode *inode, int type, bool rcu);
1236 int fuse_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
1237 struct posix_acl *acl, int type);
1240 int fuse_readdir(struct file *file, struct dir_context *ctx);
1243 * Return the number of bytes in an arguments list
1245 unsigned int fuse_len_args(unsigned int numargs, struct fuse_arg *args);
1248 * Get the next unique ID for a request
1250 u64 fuse_get_unique(struct fuse_iqueue *fiq);
1251 void fuse_free_conn(struct fuse_conn *fc);
1255 #define FUSE_IS_DAX(inode) (IS_ENABLED(CONFIG_FUSE_DAX) && IS_DAX(inode))
1257 ssize_t fuse_dax_read_iter(struct kiocb *iocb, struct iov_iter *to);
1258 ssize_t fuse_dax_write_iter(struct kiocb *iocb, struct iov_iter *from);
1259 int fuse_dax_mmap(struct file *file, struct vm_area_struct *vma);
1260 int fuse_dax_break_layouts(struct inode *inode, u64 dmap_start, u64 dmap_end);
1261 int fuse_dax_conn_alloc(struct fuse_conn *fc, struct dax_device *dax_dev);
1262 void fuse_dax_conn_free(struct fuse_conn *fc);
1263 bool fuse_dax_inode_alloc(struct super_block *sb, struct fuse_inode *fi);
1264 void fuse_dax_inode_init(struct inode *inode);
1265 void fuse_dax_inode_cleanup(struct inode *inode);
1266 bool fuse_dax_check_alignment(struct fuse_conn *fc, unsigned int map_alignment);
1267 void fuse_dax_cancel_work(struct fuse_conn *fc);
1270 long fuse_file_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
1271 long fuse_file_compat_ioctl(struct file *file, unsigned int cmd,
1273 int fuse_fileattr_get(struct dentry *dentry, struct fileattr *fa);
1274 int fuse_fileattr_set(struct user_namespace *mnt_userns,
1275 struct dentry *dentry, struct fileattr *fa);
1279 struct fuse_file *fuse_file_open(struct fuse_mount *fm, u64 nodeid,
1280 unsigned int open_flags, bool isdir);
1281 void fuse_file_release(struct inode *inode, struct fuse_file *ff,
1282 unsigned int open_flags, fl_owner_t id, bool isdir);
1284 #endif /* _FS_FUSE_I_H */