/* FUSE: Filesystem in Userspace Copyright (C) 2001-2008 Miklos Szeredi This program can be distributed under the terms of the GNU GPL. See the file COPYING. */ #ifndef _FS_FUSE_I_H #define _FS_FUSE_I_H #ifndef pr_fmt # define pr_fmt(fmt) "fuse: " fmt #endif #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /** Default max number of pages that can be used in a single read request */ #define FUSE_DEFAULT_MAX_PAGES_PER_REQ 32 /** Maximum of max_pages received in init_out */ #define FUSE_MAX_MAX_PAGES 256 /** Bias for fi->writectr, meaning new writepages must not be sent */ #define FUSE_NOWRITE INT_MIN /** It could be as large as PATH_MAX, but would that have any uses? */ #define FUSE_NAME_MAX 1024 /** Number of dentries for each connection in the control filesystem */ #define FUSE_CTL_NUM_DENTRIES 5 /** List of active connections */ extern struct list_head fuse_conn_list; /** Global mutex protecting fuse_conn_list and the control filesystem */ extern struct mutex fuse_mutex; /** Module parameters */ extern unsigned max_user_bgreq; extern unsigned max_user_congthresh; /* One forget request */ struct fuse_forget_link { struct fuse_forget_one forget_one; struct fuse_forget_link *next; }; /** FUSE inode */ struct fuse_inode { /** Inode data */ struct inode inode; /** Unique ID, which identifies the inode between userspace * and kernel */ u64 nodeid; /** Number of lookups on this inode */ u64 nlookup; /** The request used for sending the FORGET message */ struct fuse_forget_link *forget; /** Time in jiffies until the file attributes are valid */ u64 i_time; /* Which attributes are invalid */ u32 inval_mask; /** The sticky bit in inode->i_mode may have been removed, so preserve the original mode */ umode_t orig_i_mode; /** 64 bit inode number */ u64 orig_ino; /** Version of last attribute change */ u64 attr_version; union { /* Write related fields (regular file only) */ struct { /* Files usable in writepage. Protected by fi->lock */ struct list_head write_files; /* Writepages pending on truncate or fsync */ struct list_head queued_writes; /* Number of sent writes, a negative bias * (FUSE_NOWRITE) means more writes are blocked */ int writectr; /* Waitq for writepage completion */ wait_queue_head_t page_waitq; /* List of writepage requestst (pending or sent) */ struct list_head writepages; }; /* readdir cache (directory only) */ struct { /* true if fully cached */ bool cached; /* size of cache */ loff_t size; /* position at end of cache (position of next entry) */ loff_t pos; /* version of the cache */ u64 version; /* modification time of directory when cache was * started */ struct timespec64 mtime; /* iversion of directory when cache was started */ u64 iversion; /* protects above fields */ spinlock_t lock; } rdc; }; /** Miscellaneous bits describing inode state */ unsigned long state; /** Lock for serializing lookup and readdir for back compatibility*/ struct mutex mutex; /** Lock to protect write related fields */ spinlock_t lock; }; /** FUSE inode state bits */ enum { /** Advise readdirplus */ FUSE_I_ADVISE_RDPLUS, /** Initialized with readdirplus */ FUSE_I_INIT_RDPLUS, /** An operation changing file size is in progress */ FUSE_I_SIZE_UNSTABLE, }; struct fuse_conn; struct fuse_release_args; /** FUSE specific file data */ struct fuse_file { /** Fuse connection for this file */ struct fuse_conn *fc; /* Argument space reserved for release */ struct fuse_release_args *release_args; /** Kernel file handle guaranteed to be unique */ u64 kh; /** File handle used by userspace */ u64 fh; /** Node id of this file */ u64 nodeid; /** Refcount */ refcount_t count; /** FOPEN_* flags returned by open */ u32 open_flags; /** Entry on inode's write_files list */ struct list_head write_entry; /* Readdir related */ struct { /* * Protects below fields against (crazy) parallel readdir on * same open file. Uncontended in the normal case. */ struct mutex lock; /* Dir stream position */ loff_t pos; /* Offset in cache */ loff_t cache_off; /* Version of cache we are reading */ u64 version; } readdir; /** RB node to be linked on fuse_conn->polled_files */ struct rb_node polled_node; /** Wait queue head for poll */ wait_queue_head_t poll_wait; /** Has flock been performed on this file? */ bool flock:1; }; /** One input argument of a request */ struct fuse_in_arg { unsigned size; const void *value; }; /** One output argument of a request */ struct fuse_arg { unsigned size; void *value; }; /** FUSE page descriptor */ struct fuse_page_desc { unsigned int length; unsigned int offset; }; struct fuse_args { uint64_t nodeid; uint32_t opcode; unsigned short in_numargs; unsigned short out_numargs; bool force:1; bool noreply:1; bool nocreds:1; bool in_pages:1; bool out_pages:1; bool out_argvar:1; bool page_zeroing:1; bool page_replace:1; struct fuse_in_arg in_args[3]; struct fuse_arg out_args[2]; void (*end)(struct fuse_conn *fc, struct fuse_args *args, int error); }; struct fuse_args_pages { struct fuse_args args; struct page **pages; struct fuse_page_desc *descs; unsigned int num_pages; }; #define FUSE_ARGS(args) struct fuse_args args = {} /** The request IO state (for asynchronous processing) */ struct fuse_io_priv { struct kref refcnt; int async; spinlock_t lock; unsigned reqs; ssize_t bytes; size_t size; __u64 offset; bool write; bool should_dirty; int err; struct kiocb *iocb; struct completion *done; bool blocking; }; #define FUSE_IO_PRIV_SYNC(i) \ { \ .refcnt = KREF_INIT(1), \ .async = 0, \ .iocb = i, \ } /** * Request flags * * FR_ISREPLY: set if the request has reply * FR_FORCE: force sending of the request even if interrupted * FR_BACKGROUND: request is sent in the background * FR_WAITING: request is counted as "waiting" * FR_ABORTED: the request was aborted * FR_INTERRUPTED: the request has been interrupted * FR_LOCKED: data is being copied to/from the request * FR_PENDING: request is not yet in userspace * FR_SENT: request is in userspace, waiting for an answer * FR_FINISHED: request is finished * FR_PRIVATE: request is on private list */ enum fuse_req_flag { FR_ISREPLY, FR_FORCE, FR_BACKGROUND, FR_WAITING, FR_ABORTED, FR_INTERRUPTED, FR_LOCKED, FR_PENDING, FR_SENT, FR_FINISHED, FR_PRIVATE, }; /** * A request to the client * * .waitq.lock protects the following fields: * - FR_ABORTED * - FR_LOCKED (may also be modified under fc->lock, tested under both) */ struct fuse_req { /** This can be on either pending processing or io lists in fuse_conn */ struct list_head list; /** Entry on the interrupts list */ struct list_head intr_entry; /* Input/output arguments */ struct fuse_args *args; /** refcount */ refcount_t count; /* Request flags, updated with test/set/clear_bit() */ unsigned long flags; /* The request input header */ struct { struct fuse_in_header h; } in; /* The request output header */ struct { struct fuse_out_header h; } out; /** Used to wake up the task waiting for completion of request*/ wait_queue_head_t waitq; }; struct fuse_iqueue { /** Connection established */ unsigned connected; /** Lock protecting accesses to members of this structure */ spinlock_t lock; /** Readers of the connection are waiting on this */ wait_queue_head_t waitq; /** The next unique request id */ u64 reqctr; /** The list of pending requests */ struct list_head pending; /** Pending interrupts */ struct list_head interrupts; /** Queue of pending forgets */ struct fuse_forget_link forget_list_head; struct fuse_forget_link *forget_list_tail; /** Batching of FORGET requests (positive indicates FORGET batch) */ int forget_batch; /** O_ASYNC requests */ struct fasync_struct *fasync; }; #define FUSE_PQ_HASH_BITS 8 #define FUSE_PQ_HASH_SIZE (1 << FUSE_PQ_HASH_BITS) struct fuse_pqueue { /** Connection established */ unsigned connected; /** Lock protecting accessess to members of this structure */ spinlock_t lock; /** Hash table of requests being processed */ struct list_head *processing; /** The list of requests under I/O */ struct list_head io; }; /** * Fuse device instance */ struct fuse_dev { /** Fuse connection for this device */ struct fuse_conn *fc; /** Processing queue */ struct fuse_pqueue pq; /** list entry on fc->devices */ struct list_head entry; }; /** * A Fuse connection. * * This structure is created, when the filesystem is mounted, and is * destroyed, when the client device is closed and the filesystem is * unmounted. */ struct fuse_conn { /** Lock protecting accessess to members of this structure */ spinlock_t lock; /** Refcount */ refcount_t count; /** Number of fuse_dev's */ atomic_t dev_count; struct rcu_head rcu; /** The user id for this mount */ kuid_t user_id; /** The group id for this mount */ kgid_t group_id; /** The pid namespace for this mount */ struct pid_namespace *pid_ns; /** The user namespace for this mount */ struct user_namespace *user_ns; /** Maximum read size */ unsigned max_read; /** Maximum write size */ unsigned max_write; /** Maxmum number of pages that can be used in a single request */ unsigned int max_pages; /** Input queue */ struct fuse_iqueue iq; /** The next unique kernel file handle */ atomic64_t khctr; /** rbtree of fuse_files waiting for poll events indexed by ph */ struct rb_root polled_files; /** Maximum number of outstanding background requests */ unsigned max_background; /** Number of background requests at which congestion starts */ unsigned congestion_threshold; /** Number of requests currently in the background */ unsigned num_background; /** Number of background requests currently queued for userspace */ unsigned active_background; /** The list of background requests set aside for later queuing */ struct list_head bg_queue; /** Protects: max_background, congestion_threshold, num_background, * active_background, bg_queue, blocked */ spinlock_t bg_lock; /** Flag indicating that INIT reply has been received. Allocating * any fuse request will be suspended until the flag is set */ int initialized; /** Flag indicating if connection is blocked. This will be the case before the INIT reply is received, and if there are too many outstading backgrounds requests */ int blocked; /** waitq for blocked connection */ wait_queue_head_t blocked_waitq; /** Connection established, cleared on umount, connection abort and device release */ unsigned connected; /** Connection aborted via sysfs */ bool aborted; /** Connection failed (version mismatch). Cannot race with setting other bitfields since it is only set once in INIT reply, before any other request, and never cleared */ unsigned conn_error:1; /** Connection successful. Only set in INIT */ unsigned conn_init:1; /** Do readpages asynchronously? Only set in INIT */ unsigned async_read:1; /** Return an unique read error after abort. Only set in INIT */ unsigned abort_err:1; /** Do not send separate SETATTR request before open(O_TRUNC) */ unsigned atomic_o_trunc:1; /** Filesystem supports NFS exporting. Only set in INIT */ unsigned export_support:1; /** write-back cache policy (default is write-through) */ unsigned writeback_cache:1; /** allow parallel lookups and readdir (default is serialized) */ unsigned parallel_dirops:1; /** handle fs handles killing suid/sgid/cap on write/chown/trunc */ unsigned handle_killpriv:1; /** cache READLINK responses in page cache */ unsigned cache_symlinks:1; /* * The following bitfields are only for optimization purposes * and hence races in setting them will not cause malfunction */ /** Is open/release not implemented by fs? */ unsigned no_open:1; /** Is opendir/releasedir not implemented by fs? */ unsigned no_opendir:1; /** Is fsync not implemented by fs? */ unsigned no_fsync:1; /** Is fsyncdir not implemented by fs? */ unsigned no_fsyncdir:1; /** Is flush not implemented by fs? */ unsigned no_flush:1; /** Is setxattr not implemented by fs? */ unsigned no_setxattr:1; /** Is getxattr not implemented by fs? */ unsigned no_getxattr:1; /** Is listxattr not implemented by fs? */ unsigned no_listxattr:1; /** Is removexattr not implemented by fs? */ unsigned no_removexattr:1; /** Are posix file locking primitives not implemented by fs? */ unsigned no_lock:1; /** Is access not implemented by fs? */ unsigned no_access:1; /** Is create not implemented by fs? */ unsigned no_create:1; /** Is interrupt not implemented by fs? */ unsigned no_interrupt:1; /** Is bmap not implemented by fs? */ unsigned no_bmap:1; /** Is poll not implemented by fs? */ unsigned no_poll:1; /** Do multi-page cached writes */ unsigned big_writes:1; /** Don't apply umask to creation modes */ unsigned dont_mask:1; /** Are BSD file locking primitives not implemented by fs? */ unsigned no_flock:1; /** Is fallocate not implemented by fs? */ unsigned no_fallocate:1; /** Is rename with flags implemented by fs? */ unsigned no_rename2:1; /** Use enhanced/automatic page cache invalidation. */ unsigned auto_inval_data:1; /** Filesystem is fully reponsible for page cache invalidation. */ unsigned explicit_inval_data:1; /** Does the filesystem support readdirplus? */ unsigned do_readdirplus:1; /** Does the filesystem want adaptive readdirplus? */ unsigned readdirplus_auto:1; /** Does the filesystem support asynchronous direct-IO submission? */ unsigned async_dio:1; /** Is lseek not implemented by fs? */ unsigned no_lseek:1; /** Does the filesystem support posix acls? */ unsigned posix_acl:1; /** Check permissions based on the file mode or not? */ unsigned default_permissions:1; /** Allow other than the mounter user to access the filesystem ? */ unsigned allow_other:1; /** Does the filesystem support copy_file_range? */ unsigned no_copy_file_range:1; /* Send DESTROY request */ unsigned int destroy:1; /** The number of requests waiting for completion */ atomic_t num_waiting; /** Negotiated minor version */ unsigned minor; /** Entry on the fuse_conn_list */ struct list_head entry; /** Device ID from super block */ dev_t dev; /** Dentries in the control filesystem */ struct dentry *ctl_dentry[FUSE_CTL_NUM_DENTRIES]; /** number of dentries used in the above array */ int ctl_ndents; /** Key for lock owner ID scrambling */ u32 scramble_key[4]; /** Version counter for attribute changes */ atomic64_t attr_version; /** Called on final put */ void (*release)(struct fuse_conn *); /** Super block for this connection. */ struct super_block *sb; /** Read/write semaphore to hold when accessing sb. */ struct rw_semaphore killsb; /** List of device instances belonging to this connection */ struct list_head devices; }; static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb) { return sb->s_fs_info; } static inline struct fuse_conn *get_fuse_conn(struct inode *inode) { return get_fuse_conn_super(inode->i_sb); } static inline struct fuse_inode *get_fuse_inode(struct inode *inode) { return container_of(inode, struct fuse_inode, inode); } static inline u64 get_node_id(struct inode *inode) { return get_fuse_inode(inode)->nodeid; } static inline int invalid_nodeid(u64 nodeid) { return !nodeid || nodeid == FUSE_ROOT_ID; } static inline u64 fuse_get_attr_version(struct fuse_conn *fc) { return atomic64_read(&fc->attr_version); } /** Device operations */ extern const struct file_operations fuse_dev_operations; extern const struct dentry_operations fuse_dentry_operations; extern const struct dentry_operations fuse_root_dentry_operations; /** * Inode to nodeid comparison. */ int fuse_inode_eq(struct inode *inode, void *_nodeidp); /** * Get a filled in inode */ struct inode *fuse_iget(struct super_block *sb, u64 nodeid, int generation, struct fuse_attr *attr, u64 attr_valid, u64 attr_version); int fuse_lookup_name(struct super_block *sb, u64 nodeid, const struct qstr *name, struct fuse_entry_out *outarg, struct inode **inode); /** * Send FORGET command */ void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget, u64 nodeid, u64 nlookup); struct fuse_forget_link *fuse_alloc_forget(void); struct fuse_forget_link *fuse_dequeue_forget(struct fuse_iqueue *fiq, unsigned int max, unsigned int *countp); /* * Initialize READ or READDIR request */ struct fuse_io_args { union { struct { struct fuse_read_in in; u64 attr_ver; } read; struct { struct fuse_write_in in; struct fuse_write_out out; } write; }; struct fuse_args_pages ap; struct fuse_io_priv *io; struct fuse_file *ff; }; void fuse_read_args_fill(struct fuse_io_args *ia, struct file *file, loff_t pos, size_t count, int opcode); /** * Send OPEN or OPENDIR request */ int fuse_open_common(struct inode *inode, struct file *file, bool isdir); struct fuse_file *fuse_file_alloc(struct fuse_conn *fc); void fuse_file_free(struct fuse_file *ff); void fuse_finish_open(struct inode *inode, struct file *file); void fuse_sync_release(struct fuse_inode *fi, struct fuse_file *ff, int flags); /** * Send RELEASE or RELEASEDIR request */ void fuse_release_common(struct file *file, bool isdir); /** * Send FSYNC or FSYNCDIR request */ int fuse_fsync_common(struct file *file, loff_t start, loff_t end, int datasync, int opcode); /** * Notify poll wakeup */ int fuse_notify_poll_wakeup(struct fuse_conn *fc, struct fuse_notify_poll_wakeup_out *outarg); /** * Initialize file operations on a regular file */ void fuse_init_file_inode(struct inode *inode); /** * Initialize inode operations on regular files and special files */ void fuse_init_common(struct inode *inode); /** * Initialize inode and file operations on a directory */ void fuse_init_dir(struct inode *inode); /** * Initialize inode operations on a symlink */ void fuse_init_symlink(struct inode *inode); /** * Change attributes of an inode */ void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr, u64 attr_valid, u64 attr_version); void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr, u64 attr_valid); /** * Initialize the client device */ int fuse_dev_init(void); /** * Cleanup the client device */ void fuse_dev_cleanup(void); int fuse_ctl_init(void); void __exit fuse_ctl_cleanup(void); /** * Simple request sending that does request allocation and freeing */ ssize_t fuse_simple_request(struct fuse_conn *fc, struct fuse_args *args); int fuse_simple_background(struct fuse_conn *fc, struct fuse_args *args, gfp_t gfp_flags); /** * End a finished request */ void fuse_request_end(struct fuse_conn *fc, struct fuse_req *req); /* Abort all requests */ void fuse_abort_conn(struct fuse_conn *fc); void fuse_wait_aborted(struct fuse_conn *fc); /** * Invalidate inode attributes */ void fuse_invalidate_attr(struct inode *inode); void fuse_invalidate_entry_cache(struct dentry *entry); void fuse_invalidate_atime(struct inode *inode); u64 entry_attr_timeout(struct fuse_entry_out *o); void fuse_change_entry_timeout(struct dentry *entry, struct fuse_entry_out *o); /** * Acquire reference to fuse_conn */ struct fuse_conn *fuse_conn_get(struct fuse_conn *fc); /** * Initialize fuse_conn */ void fuse_conn_init(struct fuse_conn *fc, struct user_namespace *user_ns); /** * Release reference to fuse_conn */ void fuse_conn_put(struct fuse_conn *fc); struct fuse_dev *fuse_dev_alloc(struct fuse_conn *fc); void fuse_dev_free(struct fuse_dev *fud); void fuse_send_init(struct fuse_conn *fc); /** * Add connection to control filesystem */ int fuse_ctl_add_conn(struct fuse_conn *fc); /** * Remove connection from control filesystem */ void fuse_ctl_remove_conn(struct fuse_conn *fc); /** * Is file type valid? */ int fuse_valid_type(int m); /** * Is current process allowed to perform filesystem operation? */ int fuse_allow_current_process(struct fuse_conn *fc); u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id); void fuse_update_ctime(struct inode *inode); int fuse_update_attributes(struct inode *inode, struct file *file); void fuse_flush_writepages(struct inode *inode); void fuse_set_nowrite(struct inode *inode); void fuse_release_nowrite(struct inode *inode); /** * File-system tells the kernel to invalidate cache for the given node id. */ int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid, loff_t offset, loff_t len); /** * File-system tells the kernel to invalidate parent attributes and * the dentry matching parent/name. * * If the child_nodeid is non-zero and: * - matches the inode number for the dentry matching parent/name, * - is not a mount point * - is a file or oan empty directory * then the dentry is unhashed (d_delete()). */ int fuse_reverse_inval_entry(struct super_block *sb, u64 parent_nodeid, u64 child_nodeid, struct qstr *name); int fuse_do_open(struct fuse_conn *fc, u64 nodeid, struct file *file, bool isdir); /** * fuse_direct_io() flags */ /** If set, it is WRITE; otherwise - READ */ #define FUSE_DIO_WRITE (1 << 0) /** CUSE pass fuse_direct_io() a file which f_mapping->host is not from FUSE */ #define FUSE_DIO_CUSE (1 << 1) ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter, loff_t *ppos, int flags); long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg, unsigned int flags); long fuse_ioctl_common(struct file *file, unsigned int cmd, unsigned long arg, unsigned int flags); __poll_t fuse_file_poll(struct file *file, poll_table *wait); int fuse_dev_release(struct inode *inode, struct file *file); bool fuse_write_update_size(struct inode *inode, loff_t pos); int fuse_flush_times(struct inode *inode, struct fuse_file *ff); int fuse_write_inode(struct inode *inode, struct writeback_control *wbc); int fuse_do_setattr(struct dentry *dentry, struct iattr *attr, struct file *file); void fuse_set_initialized(struct fuse_conn *fc); void fuse_unlock_inode(struct inode *inode, bool locked); bool fuse_lock_inode(struct inode *inode); int fuse_setxattr(struct inode *inode, const char *name, const void *value, size_t size, int flags); ssize_t fuse_getxattr(struct inode *inode, const char *name, void *value, size_t size); ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size); int fuse_removexattr(struct inode *inode, const char *name); extern const struct xattr_handler *fuse_xattr_handlers[]; extern const struct xattr_handler *fuse_acl_xattr_handlers[]; extern const struct xattr_handler *fuse_no_acl_xattr_handlers[]; struct posix_acl; struct posix_acl *fuse_get_acl(struct inode *inode, int type); int fuse_set_acl(struct inode *inode, struct posix_acl *acl, int type); /* readdir.c */ int fuse_readdir(struct file *file, struct dir_context *ctx); /** * Return the number of bytes in an arguments list */ unsigned int fuse_len_args(unsigned int numargs, struct fuse_arg *args); /** * Get the next unique ID for a request */ u64 fuse_get_unique(struct fuse_iqueue *fiq); #endif /* _FS_FUSE_I_H */