/*
FUSE: Filesystem in Userspace
- Copyright (C) 2001-2005 Miklos Szeredi <miklos@szeredi.hu>
+ Copyright (C) 2001-2006 Miklos Szeredi <miklos@szeredi.hu>
This program can be distributed under the terms of the GNU GPL.
See the file COPYING.
/** 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
+/** Maximum number of outstanding background requests */
+#define FUSE_MAX_BACKGROUND 10
/** It could be as large as PATH_MAX, but would that have any uses? */
#define FUSE_NAME_MAX 1024
/** 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;
struct fuse_arg args[3];
};
+/** The request state */
+enum fuse_req_state {
+ FUSE_REQ_INIT = 0,
+ FUSE_REQ_PENDING,
+ FUSE_REQ_READING,
+ FUSE_REQ_SENT,
+ FUSE_REQ_FINISHED
+};
+
+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 */
+ /** This can be on either pending processing or io lists in
+ fuse_conn */
struct list_head list;
/** Entry on the background list */
/** refcount */
atomic_t count;
+ /*
+ * 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;
- /** The request is preallocated */
- unsigned preallocated:1;
-
/** The request was interrupted */
unsigned interrupted:1;
/** Data is being copied to/from the request */
unsigned locked:1;
- /** Request has been sent to userspace */
- unsigned sent:1;
+ /** Request is counted as "waiting" */
+ unsigned waiting:1;
- /** The request is finished */
- unsigned finished:1;
+ /** State of the request */
+ enum fuse_req_state state;
/** The request input */
struct fuse_in in;
struct fuse_release_in release_in;
struct fuse_init_in init_in;
struct fuse_init_out init_out;
+ struct fuse_read_in read_in;
} misc;
/** page vector */
/** File used in the request (or NULL) */
struct file *file;
+
+ /** Request completion callback */
+ void (*end)(struct fuse_conn *, struct fuse_req *);
};
/**
* unmounted.
*/
struct fuse_conn {
- /** Reference count */
- int count;
+ /** Lock protecting accessess to members of this structure */
+ spinlock_t lock;
/** The user id for this mount */
uid_t user_id;
/** The list of requests being processed */
struct list_head processing;
+ /** The list of requests under I/O */
+ struct list_head io;
+
/** 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;
+ /** Number of requests currently in the background */
+ unsigned num_background;
+
+ /** 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;
- /** This counts the number of outstanding requests if
- outstanding_sem would go negative */
- unsigned outstanding_debt;
+ /** waitq for blocked connection */
+ wait_queue_head_t blocked_waitq;
/** 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;
+ unsigned mounted;
- /** Connection established */
- unsigned connected : 1;
+ /** Connection established, cleared on umount, connection
+ abort and device release */
+ unsigned connected;
- /** Connection failed (version mismatch) */
+ /** 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;
+ /** Do readpages asynchronously? Only set in INIT */
+ unsigned async_read : 1;
+
+ /*
+ * The following bitfields are only for optimization purposes
+ * and hence races in setting them will not cause malfunction
+ */
+
/** Is fsync not implemented by fs? */
unsigned no_fsync : 1;
/** Is create not implemented by fs? */
unsigned no_create : 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;
-};
-static inline struct fuse_conn **get_fuse_conn_super_p(struct super_block *sb)
-{
- return (struct fuse_conn **) &sb->s_fs_info;
-}
+ /** kobject */
+ struct kobject kobj;
+
+ /** O_ASYNC requests */
+ struct fasync_struct *fasync;
+};
static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
{
- return *get_fuse_conn_super_p(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_conn *get_fuse_conn_kobj(struct kobject *obj)
+{
+ return container_of(obj, struct fuse_conn, kobj);
+}
+
static inline struct fuse_inode *get_fuse_inode(struct inode *inode)
{
return container_of(inode, struct fuse_inode, inode);
}
/** 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;
+extern const struct file_operations fuse_dev_operations;
/**
* Get a filled in inode
unsigned long nodeid, u64 nlookup);
/**
- * Send READ or READDIR request
+ * Initialize 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);
+void fuse_read_fill(struct fuse_req *req, struct file *file,
+ struct inode *inode, loff_t pos, size_t count, int opcode);
/**
* Send OPEN or OPENDIR request
*/
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
*/
/**
* Reserve a preallocated request
*/
-struct fuse_req *fuse_get_request(struct fuse_conn *fc);
+struct fuse_req *fuse_get_req(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).
+ * 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);
/**
* Release inodes and file associated with background request
*/
-void fuse_release_background(struct fuse_req *req);
+void fuse_release_background(struct fuse_conn *fc, struct fuse_req *req);
+
+/* Abort all requests */
+void fuse_abort_conn(struct fuse_conn *fc);
/**
* Get the attributes of a file
* Invalidate inode attributes
*/
void fuse_invalidate_attr(struct inode *inode);
-
-/**
- * Send the INIT message
- */
-void fuse_send_init(struct fuse_conn *fc);