/*
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.
#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 <asm/semaphore.h>
+#include <linux/mutex.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
+/** 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
+
+/** Number of dentries for each connection in the control filesystem */
+#define FUSE_CTL_NUM_DENTRIES 3
/** If the FUSE_DEFAULT_PERMISSIONS flag is given, the filesystem
module will check permissions based on the file mode. Otherwise no
doing the mount will be allowed to access the filesystem */
#define FUSE_ALLOW_OTHER (1 << 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;
/** FUSE inode */
struct fuse_inode {
struct fuse_req *forget_req;
/** Time in jiffies until the file attributes are valid */
- unsigned long i_time;
+ u64 i_time;
};
/** FUSE specific file data */
struct fuse_file {
/** Request reserved for flush and release */
- struct fuse_req *release_req;
+ struct fuse_req *reserved_req;
/** File handle used by userspace */
u64 fh;
/** 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];
};
-struct fuse_req;
+/** 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
+};
+
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 */
- struct list_head bg_entry;
+ /** 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;
- /** The request is preallocated */
- unsigned preallocated:1;
+ /** Force sending of the request even if interrupted */
+ unsigned force:1;
- /** The request was interrupted */
- unsigned interrupted: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 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;
union {
struct fuse_forget_in forget_in;
struct fuse_release_in release_in;
- struct fuse_init_in_out init_in_out;
+ struct fuse_init_in init_in;
+ struct fuse_init_out init_out;
+ struct fuse_read_in read_in;
+ struct fuse_lk_in lk_in;
} misc;
/** page vector */
/** 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;
+
+ /** vfsmount used in release */
+ struct vfsmount *vfsmount;
+
+ /** dentry used in release */
+ struct dentry *dentry;
+
+ /** Request completion callback */
+ void (*end)(struct fuse_conn *, struct fuse_req *);
+
+ /** Request is stolen from fuse_file->reserved_req */
+ struct file *stolen_file;
};
/**
* unmounted.
*/
struct fuse_conn {
- /** Reference count */
- int count;
+ /** Lock protecting accessess to members of this structure */
+ spinlock_t lock;
+
+ /** Refcount */
+ atomic_t count;
/** The user id for this mount */
uid_t user_id;
/** 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;
+ /** The list of requests under I/O */
+ struct list_head io;
- /** Controls the maximum number of outstanding requests */
- struct semaphore outstanding_sem;
+ /** Number of requests currently in the background */
+ unsigned num_background;
- /** This counts the number of outstanding requests if
- outstanding_sem would go negative */
- unsigned outstanding_debt;
+ /** Pending interrupts */
+ struct list_head interrupts;
- /** RW semaphore for exclusion with fuse_put_super() */
- struct rw_semaphore sbput_sem;
+ /** 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;
- /** The list of unused requests */
- struct list_head unused_list;
+ /** waitq for blocked connection */
+ wait_queue_head_t blocked_waitq;
/** The next unique request id */
u64 reqctr;
- /** Mount is active */
- unsigned mounted : 1;
+ /** Connection established, cleared on umount, connection
+ abort and device release */
+ unsigned connected;
- /** Connection established */
- unsigned connected : 1;
-
- /** 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 removexattr not implemented by fs? */
unsigned no_removexattr : 1;
+ /** Are 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;
+
+ /** 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;
-}
+ /** Entry on the fuse_conn_list */
+ struct list_head entry;
+
+ /** Unique ID */
+ u64 id;
+
+ /** 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];
+};
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)
}
/** 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
*/
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);
+
+/** */
+struct fuse_req *fuse_release_fill(struct fuse_file *ff, u64 nodeid, int flags,
+ int opcode);
/**
* Send RELEASE or RELEASEDIR 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
*/
int fuse_dev_init(void);
*/
void fuse_dev_cleanup(void);
+int fuse_ctl_init(void);
+void fuse_ctl_cleanup(void);
+
/**
* Allocate a request
*/
void fuse_request_free(struct fuse_req *req);
/**
- * Reinitialize a request, the preallocated flag is left unmodified
+ * Get a request, may fail with -ENOMEM
*/
-void fuse_reset_request(struct fuse_req *req);
+struct fuse_req *fuse_get_req(struct fuse_conn *fc);
/**
- * Reserve a preallocated request
+ * Gets a requests for a file operation, always succeeds
*/
-struct fuse_req *fuse_get_request(struct fuse_conn *fc);
+struct fuse_req *fuse_get_req_nofail(struct fuse_conn *fc, struct file *file);
/**
- * 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);
*/
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);
+/* Abort all requests */
+void fuse_abort_conn(struct fuse_conn *fc);
/**
* Get the attributes of a file
void fuse_invalidate_attr(struct inode *inode);
/**
- * Send the INIT message
+ * Acquire reference to fuse_conn
+ */
+struct fuse_conn *fuse_conn_get(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_send_init(struct fuse_conn *fc);
+void fuse_ctl_remove_conn(struct fuse_conn *fc);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff