/* 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 #include #include #include #include #include #include #include #include #include #include #include #include #include /** Max number of pages that can be used in a single read request */ #define FUSE_MAX_PAGES_PER_REQ 32 /** 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 /** If the FUSE_DEFAULT_PERMISSIONS flag is given, the filesystem module will check permissions based on the file mode. Otherwise no permission checking is done in the kernel */ #define FUSE_DEFAULT_PERMISSIONS (1 << 0) /** If the FUSE_ALLOW_OTHER flag is given, then not only the user doing the mount will be allowed to access the filesystem */ #define FUSE_ALLOW_OTHER (1 << 1) /** Number of page pointers embedded in fuse_req */ #define FUSE_REQ_INLINE_PAGES 1 /** 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; /** 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; /** Files usable in writepage. Protected by fc->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; /** Miscellaneous bits describing inode state */ unsigned long state; }; /** 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; /** FUSE specific file data */ struct fuse_file { /** Fuse connection for this file */ struct fuse_conn *fc; /** Request reserved for flush and release */ struct fuse_req *reserved_req; /** Kernel file handle guaranteed to be unique */ u64 kh; /** File handle used by userspace */ u64 fh; /** Node id of this file */ u64 nodeid; /** Refcount */ atomic_t count; /** FOPEN_* flags returned by open */ u32 open_flags; /** Entry on inode's write_files list */ struct list_head write_entry; /** 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; }; /** The request input */ struct fuse_in { /** The request header */ struct fuse_in_header h; /** True if the data for the last argument is in req->pages */ unsigned argpages:1; /** Number of arguments */ unsigned numargs; /** Array of arguments */ struct fuse_in_arg args[3]; }; /** One output argument of a request */ struct fuse_arg { unsigned size; void *value; }; /** The request output */ struct fuse_out { /** Header returned from userspace */ struct fuse_out_header h; /* * The following bitfields are not changed during the request * processing */ /** Last argument is variable length (can be shorter than arg->size) */ unsigned argvar:1; /** Last argument is a list of pages to copy data to */ unsigned argpages:1; /** Zero partially or not copied pages */ unsigned page_zeroing:1; /** Pages may be replaced with new ones */ unsigned page_replace:1; /** Number or arguments */ unsigned numargs; /** Array of arguments */ struct fuse_arg args[3]; }; /** FUSE page descriptor */ struct fuse_page_desc { unsigned int length; unsigned int offset; }; /** The request state */ enum fuse_req_state { FUSE_REQ_INIT = 0, FUSE_REQ_PENDING, FUSE_REQ_READING, FUSE_REQ_SENT, FUSE_REQ_WRITING, FUSE_REQ_FINISHED }; /** The request IO state (for asynchronous processing) */ struct fuse_io_priv { int async; spinlock_t lock; unsigned reqs; ssize_t bytes; size_t size; __u64 offset; bool write; int err; struct kiocb *iocb; struct file *file; }; /** * A request to the client */ 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; /** refcount */ atomic_t count; /** Unique ID for the interrupt request */ u64 intr_unique; /* * The following bitfields are either set once before the * request is queued or setting/clearing them is protected by * fuse_conn->lock */ /** True if the request has reply */ unsigned isreply:1; /** Force sending of the request even if interrupted */ unsigned force:1; /** The request was aborted */ unsigned aborted:1; /** Request is sent in the background */ unsigned background:1; /** The request has been interrupted */ unsigned interrupted:1; /** Data is being copied to/from the request */ unsigned locked:1; /** Request is counted as "waiting" */ unsigned waiting:1; /** State of the request */ enum fuse_req_state state; /** The request input */ struct fuse_in in; /** The request output */ struct fuse_out out; /** Used to wake up the task waiting for completion of request*/ wait_queue_head_t waitq; /** Data for asynchronous requests */ union { struct { union { struct fuse_release_in in; struct work_struct work; }; struct path path; } release; struct fuse_init_in init_in; struct fuse_init_out init_out; struct cuse_init_in cuse_init_in; struct { struct fuse_read_in in; u64 attr_ver; } read; struct { struct fuse_write_in in; struct fuse_write_out out; struct fuse_req *next; } write; struct fuse_notify_retrieve_in retrieve_in; struct fuse_lk_in lk_in; } misc; /** page vector */ struct page **pages; /** page-descriptor vector */ struct fuse_page_desc *page_descs; /** size of the 'pages' array */ unsigned max_pages; /** inline page vector */ struct page *inline_pages[FUSE_REQ_INLINE_PAGES]; /** inline page-descriptor vector */ struct fuse_page_desc inline_page_descs[FUSE_REQ_INLINE_PAGES]; /** number of pages in vector */ unsigned num_pages; /** File used in the request (or NULL) */ struct fuse_file *ff; /** Inode used in the request or NULL */ struct inode *inode; /** AIO control block */ struct fuse_io_priv *io; /** Link on fi->writepages */ struct list_head writepages_entry; /** Request completion callback */ void (*end)(struct fuse_conn *, struct fuse_req *); /** Request is stolen from fuse_file->reserved_req */ struct file *stolen_file; }; /** * 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 */ atomic_t 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 fuse mount flags for this mount */ unsigned flags; /** Maximum read size */ unsigned max_read; /** Maximum write size */ unsigned max_write; /** Readers of the connection are waiting on this */ wait_queue_head_t waitq; /** The list of pending requests */ struct list_head pending; /** The list of requests being processed */ struct list_head processing; /** The list of requests under I/O */ struct list_head io; /** The next unique kernel file handle */ u64 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; /** 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; /** 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; /** waitq for reserved requests */ wait_queue_head_t reserved_req_waitq; /** The next unique request id */ u64 reqctr; /** Connection established, cleared on umount, connection abort and device release */ unsigned connected; /** 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; /** 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; /** Set if bdi is valid */ unsigned bdi_initialized:1; /** write-back cache policy (default is write-through) */ unsigned writeback_cache: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 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; /** Use enhanced/automatic page cache invalidation. */ unsigned auto_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; /** The number of requests waiting for completion */ atomic_t num_waiting; /** Negotiated minor version */ unsigned minor; /** Backing dev info */ struct backing_dev_info bdi; /** 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; /** O_ASYNC requests */ struct fasync_struct *fasync; /** Key for lock owner ID scrambling */ u32 scramble_key[4]; /** Reserved request for the DESTROY message */ struct fuse_req *destroy_req; /** Version counter for attribute changes */ u64 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; }; 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; } /** Device operations */ extern const struct file_operations fuse_dev_operations; extern const struct dentry_operations fuse_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, 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); /* Used by READDIRPLUS */ void fuse_force_forget(struct file *file, u64 nodeid); /** * Initialize READ or READDIR request */ void fuse_read_fill(struct fuse_req *req, 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); struct fuse_file *fuse_file_get(struct fuse_file *ff); void fuse_file_free(struct fuse_file *ff); void fuse_finish_open(struct inode *inode, struct file *file); void fuse_sync_release(struct fuse_file *ff, int flags); /** * Send RELEASE or RELEASEDIR request */ void fuse_release_common(struct file *file, int opcode); /** * Send FSYNC or FSYNCDIR request */ int fuse_fsync_common(struct file *file, loff_t start, loff_t end, int datasync, int isdir); /** * 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 fuse_ctl_cleanup(void); /** * Allocate a request */ struct fuse_req *fuse_request_alloc(unsigned npages); struct fuse_req *fuse_request_alloc_nofs(unsigned npages); /** * Free a request */ void fuse_request_free(struct fuse_req *req); /** * Get a request, may fail with -ENOMEM, * caller should specify # elements in req->pages[] explicitly */ struct fuse_req *fuse_get_req(struct fuse_conn *fc, unsigned npages); struct fuse_req *fuse_get_req_for_background(struct fuse_conn *fc, unsigned npages); /* * Increment reference count on request */ void __fuse_get_request(struct fuse_req *req); /** * Get a request, may fail with -ENOMEM, * useful for callers who doesn't use req->pages[] */ static inline struct fuse_req *fuse_get_req_nopages(struct fuse_conn *fc) { return fuse_get_req(fc, 0); } /** * Gets a requests for a file operation, always succeeds */ struct fuse_req *fuse_get_req_nofail_nopages(struct fuse_conn *fc, struct file *file); /** * Decrement reference count of a request. If count goes to zero free * the request. */ void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req); /** * Send a request (synchronous) */ void fuse_request_send(struct fuse_conn *fc, struct fuse_req *req); /** * Send a request in the background */ void fuse_request_send_background(struct fuse_conn *fc, struct fuse_req *req); void fuse_request_send_background_locked(struct fuse_conn *fc, struct fuse_req *req); /* Abort all requests */ void fuse_abort_conn(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); /** * Acquire reference to fuse_conn */ struct fuse_conn *fuse_conn_get(struct fuse_conn *fc); void fuse_conn_kill(struct fuse_conn *fc); /** * Initialize fuse_conn */ void fuse_conn_init(struct fuse_conn *fc); /** * Release reference to fuse_conn */ void fuse_conn_put(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); int fuse_update_attributes(struct inode *inode, struct kstat *stat, struct file *file, bool *refreshed); void fuse_flush_writepages(struct inode *inode); void fuse_set_nowrite(struct inode *inode); void fuse_release_nowrite(struct inode *inode); u64 fuse_get_attr_version(struct fuse_conn *fc); /** * 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); ssize_t fuse_direct_io(struct fuse_io_priv *io, const struct iovec *iov, unsigned long nr_segs, size_t count, loff_t *ppos, int write); 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); unsigned fuse_file_poll(struct file *file, poll_table *wait); int fuse_dev_release(struct inode *inode, struct file *file); void fuse_write_update_size(struct inode *inode, loff_t pos); int fuse_do_setattr(struct inode *inode, struct iattr *attr, struct file *file); #endif /* _FS_FUSE_I_H */