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Diffstat (limited to 'fs/fuse/fuse_i.h')
| -rw-r--r-- | fs/fuse/fuse_i.h | 912 |
1 files changed, 912 insertions, 0 deletions
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h new file mode 100644 index 000000000..7354dc142 --- /dev/null +++ b/fs/fuse/fuse_i.h @@ -0,0 +1,912 @@ +/* + FUSE: Filesystem in Userspace + Copyright (C) 2001-2008 Miklos Szeredi <miklos@szeredi.hu> + + 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 <linux/fuse.h> +#include <linux/fs.h> +#include <linux/mount.h> +#include <linux/wait.h> +#include <linux/list.h> +#include <linux/spinlock.h> +#include <linux/mm.h> +#include <linux/backing-dev.h> +#include <linux/mutex.h> +#include <linux/rwsem.h> +#include <linux/rbtree.h> +#include <linux/poll.h> +#include <linux/workqueue.h> + +/** 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[2]; +}; + +/** FUSE page descriptor */ +struct fuse_page_desc { + unsigned int length; + unsigned int offset; +}; + +struct fuse_args { + struct { + struct { + uint32_t opcode; + uint64_t nodeid; + } h; + unsigned numargs; + struct fuse_in_arg args[3]; + + } in; + struct { + unsigned argvar:1; + unsigned numargs; + struct fuse_arg args[2]; + } out; +}; + +#define FUSE_ARGS(args) struct fuse_args args = {} + +/** 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; + struct completion *done; +}; + +/** + * 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 { + struct fuse_release_in in; + struct inode *inode; + } 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; + } 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; + + /** Is rename with flags implemented by fs? */ + unsigned no_rename2:1; + + /** 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 __exit 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); + +/** + * 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); + +/** + * Simple request sending that does request allocation and freeing + */ +ssize_t fuse_simple_request(struct fuse_conn *fc, struct fuse_args *args); + +/** + * 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); + +/** + * 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); + +/** + * 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); +unsigned 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 inode *inode, struct iattr *attr, + struct file *file); + +void fuse_set_initialized(struct fuse_conn *fc); + +#endif /* _FS_FUSE_I_H */ |