#include <linux/backing-dev.h>
#include <asm/semaphore.h>
+/** Max number of pages that can be used in a single read request */
+#define FUSE_MAX_PAGES_PER_REQ 32
+
+/** If more requests are outstanding, then the operation will block */
+#define FUSE_MAX_OUTSTANDING 10
+
+/** 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)
+
+
/** FUSE inode */
struct fuse_inode {
/** Inode data */
* and kernel */
u64 nodeid;
+ /** Number of lookups on this inode */
+ u64 nlookup;
+
+ /** The request used for sending the FORGET message */
+ struct fuse_req *forget_req;
+
/** Time in jiffies until the file attributes are valid */
unsigned long i_time;
};
+/** FUSE specific file data */
+struct fuse_file {
+ /** Request reserved for flush and release */
+ struct fuse_req *release_req;
+
+ /** File handle used by userspace */
+ u64 fh;
+};
+
+/** 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;
+
+ /** 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;
+
+ /** Number or arguments */
+ unsigned numargs;
+
+ /** Array of arguments */
+ struct fuse_arg args[3];
+};
+
+struct fuse_req;
+struct fuse_conn;
+
+/**
+ * A request to the client
+ */
+struct fuse_req {
+ /** This can be on either unused_list, pending or processing
+ lists in fuse_conn */
+ struct list_head list;
+
+ /** Entry on the background list */
+ struct list_head bg_entry;
+
+ /** refcount */
+ atomic_t count;
+
+ /** True if the request has reply */
+ unsigned isreply:1;
+
+ /** The request is preallocated */
+ unsigned preallocated:1;
+
+ /** The request was interrupted */
+ unsigned interrupted:1;
+
+ /** Request is sent in the background */
+ unsigned background:1;
+
+ /** Data is being copied to/from the request */
+ unsigned locked:1;
+
+ /** Request has been sent to userspace */
+ unsigned sent:1;
+
+ /** The request is finished */
+ unsigned finished:1;
+
+ /** 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 fuse_forget_in forget_in;
+ struct fuse_release_in release_in;
+ struct fuse_init_in_out init_in_out;
+ } misc;
+
+ /** page vector */
+ struct page *pages[FUSE_MAX_PAGES_PER_REQ];
+
+ /** number of pages in vector */
+ unsigned num_pages;
+
+ /** offset of data on first page */
+ unsigned page_offset;
+
+ /** Inode used in the request */
+ struct inode *inode;
+
+ /** Second inode used in the request (or NULL) */
+ struct inode *inode2;
+
+ /** File used in the request (or NULL) */
+ struct file *file;
+};
+
/**
* A Fuse connection.
*
* unmounted.
*/
struct fuse_conn {
- /** The superblock of the mounted filesystem */
- struct super_block *sb;
+ /** Reference count */
+ int count;
/** The user id for this mount */
uid_t user_id;
+ /** The group id for this mount */
+ gid_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;
+
+ /** Requests put in the background (RELEASE or any other
+ interrupted request) */
+ struct list_head background;
+
+ /** Controls the maximum number of outstanding requests */
+ struct semaphore outstanding_sem;
+
+ /** This counts the number of outstanding requests if
+ outstanding_sem would go negative */
+ unsigned outstanding_debt;
+
+ /** RW semaphore for exclusion with fuse_put_super() */
+ struct rw_semaphore sbput_sem;
+
+ /** The list of unused requests */
+ struct list_head unused_list;
+
+ /** The next unique request id */
+ u64 reqctr;
+
+ /** Mount is active */
+ unsigned mounted : 1;
+
+ /** Connection established */
+ unsigned connected : 1;
+
+ /** Connection failed (version mismatch) */
+ unsigned conn_error : 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;
+
+ /** Is access not implemented by fs? */
+ unsigned no_access : 1;
+
+ /** Is create not implemented by fs? */
+ unsigned no_create : 1;
+
/** Backing dev info */
struct backing_dev_info bdi;
};
return get_fuse_inode(inode)->nodeid;
}
+/** Device operations */
+extern struct file_operations fuse_dev_operations;
+
/**
* This is the single global spinlock which protects FUSE's structures
*
* The following data is protected by this lock:
*
+ * - the private_data field of the device file
* - the s_fs_info field of the super block
+ * - unused_list, pending, processing lists in fuse_conn
+ * - background list in fuse_conn
+ * - the unique request ID counter reqctr in fuse_conn
* - the sb (super_block) field in fuse_conn
+ * - the file (device file) field in fuse_conn
*/
extern spinlock_t fuse_lock;
+/**
+ * Get a filled in inode
+ */
+struct inode *fuse_iget(struct super_block *sb, unsigned long nodeid,
+ int generation, struct fuse_attr *attr);
+
+/**
+ * Send FORGET command
+ */
+void fuse_send_forget(struct fuse_conn *fc, struct fuse_req *req,
+ unsigned long nodeid, u64 nlookup);
+
+/**
+ * Send READ or READDIR request
+ */
+size_t fuse_send_read_common(struct fuse_req *req, struct file *file,
+ struct inode *inode, loff_t pos, size_t count,
+ int isdir);
+
+/**
+ * Send OPEN or OPENDIR request
+ */
+int fuse_open_common(struct inode *inode, struct file *file, int isdir);
+
+struct fuse_file *fuse_file_alloc(void);
+void fuse_file_free(struct fuse_file *ff);
+void fuse_finish_open(struct inode *inode, struct file *file,
+ struct fuse_file *ff, struct fuse_open_out *outarg);
+
+/**
+ * Send a RELEASE request
+ */
+void fuse_send_release(struct fuse_conn *fc, struct fuse_file *ff,
+ u64 nodeid, struct inode *inode, int flags, int isdir);
+
+/**
+ * Send RELEASE or RELEASEDIR request
+ */
+int fuse_release_common(struct inode *inode, struct file *file, int isdir);
+
+/**
+ * Send FSYNC or FSYNCDIR request
+ */
+int fuse_fsync_common(struct file *file, struct dentry *de, int datasync,
+ int isdir);
+
+/**
+ * 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);
+
/**
* Check if the connection can be released, and if yes, then free the
* connection structure
*/
void fuse_release_conn(struct fuse_conn *fc);
+/**
+ * Initialize the client device
+ */
+int fuse_dev_init(void);
+
+/**
+ * Cleanup the client device
+ */
+void fuse_dev_cleanup(void);
+
+/**
+ * Allocate a request
+ */
+struct fuse_req *fuse_request_alloc(void);
+
+/**
+ * Free a request
+ */
+void fuse_request_free(struct fuse_req *req);
+
+/**
+ * Reinitialize a request, the preallocated flag is left unmodified
+ */
+void fuse_reset_request(struct fuse_req *req);
+
+/**
+ * Reserve a preallocated request
+ */
+struct fuse_req *fuse_get_request(struct fuse_conn *fc);
+
+/**
+ * Decrement reference count of a request. If count goes to zero put
+ * on unused list (preallocated) or free request (not preallocated).
+ */
+void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req);
+
+/**
+ * Send a request (synchronous)
+ */
+void request_send(struct fuse_conn *fc, struct fuse_req *req);
+
+/**
+ * Send a request with no reply
+ */
+void request_send_noreply(struct fuse_conn *fc, struct fuse_req *req);
+
+/**
+ * Send a request in the background
+ */
+void request_send_background(struct fuse_conn *fc, struct fuse_req *req);
+
+/**
+ * Release inodes and file associated with background request
+ */
+void fuse_release_background(struct fuse_req *req);
+
+/**
+ * Get the attributes of a file
+ */
+int fuse_do_getattr(struct inode *inode);
+
+/**
+ * Invalidate inode attributes
+ */
+void fuse_invalidate_attr(struct inode *inode);
+
+/**
+ * Send the INIT message
+ */
+void fuse_send_init(struct fuse_conn *fc);