linux 2.6.16.38 w/ vs2.0.3-rc1

[linux-2.6.git] / fs / fuse / fuse_i.h

diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 0474202..4a83adf 100644 (file)
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -1,6 +1,6 @@
 /*
   FUSE: Filesystem in Userspace
-  Copyright (C) 2001-2006  Miklos Szeredi <miklos@szeredi.hu>
+  Copyright (C) 2001-2005  Miklos Szeredi <miklos@szeredi.hu>
 
   This program can be distributed under the terms of the GNU GPL.
   See the file COPYING.
@@ -18,8 +18,8 @@
 /** Max number of pages that can be used in a single read request */
 #define FUSE_MAX_PAGES_PER_REQ 32
 
-/** Maximum number of outstanding background requests */
-#define FUSE_MAX_BACKGROUND 10
+/** If more requests are outstanding, then the operation will block */
+#define FUSE_MAX_OUTSTANDING 10
 
 /** It could be as large as PATH_MAX, but would that have any uses? */
 #define FUSE_NAME_MAX 1024
@@ -131,8 +131,8 @@ struct fuse_conn;
  * A request to the client
  */
 struct fuse_req {
-       /** This can be on either pending processing or io lists in
-           fuse_conn */
+       /** This can be on either unused_list, pending processing or
+           io lists in fuse_conn */
        struct list_head list;
 
        /** Entry on the background list */
@@ -144,12 +144,15 @@ struct fuse_req {
        /*
         * The following bitfields are either set once before the
         * request is queued or setting/clearing them is protected by
-        * fuse_conn->lock
+        * fuse_lock
         */
 
        /** True if the request has reply */
        unsigned isreply:1;
 
+       /** The request is preallocated */
+       unsigned preallocated:1;
+
        /** The request was interrupted */
        unsigned interrupted:1;
 
@@ -159,9 +162,6 @@ struct fuse_req {
        /** 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;
 
@@ -213,9 +213,6 @@ struct fuse_req {
  * unmounted.
  */
 struct fuse_conn {
-       /** Lock protecting accessess to  members of this structure */
-       spinlock_t lock;
-
        /** The user id for this mount */
        uid_t user_id;
 
@@ -247,20 +244,19 @@ struct fuse_conn {
            interrupted request) */
        struct list_head background;
 
-       /** Number of requests currently in the background */
-       unsigned num_background;
+       /** Controls the maximum number of outstanding requests */
+       struct semaphore outstanding_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;
-
-       /** waitq for blocked connection */
-       wait_queue_head_t blocked_waitq;
+       /** 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;
 
@@ -322,9 +318,6 @@ struct fuse_conn {
 
        /** kobject */
        struct kobject kobj;
-
-       /** O_ASYNC requests */
-       struct fasync_struct *fasync;
 };
 
 static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
@@ -353,7 +346,22 @@ static inline u64 get_node_id(struct inode *inode)
 }
 
 /** Device operations */
-extern const struct file_operations fuse_dev_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
@@ -453,11 +461,11 @@ void fuse_reset_request(struct fuse_req *req);
 /**
  * Reserve a preallocated request
  */
-struct fuse_req *fuse_get_req(struct fuse_conn *fc);
+struct fuse_req *fuse_get_request(struct fuse_conn *fc);
 
 /**
- * Decrement reference count of a request.  If count goes to zero free
- * the request.
+ * 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);
 
@@ -479,7 +487,7 @@ 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_conn *fc, struct fuse_req *req);
+void fuse_release_background(struct fuse_req *req);
 
 /* Abort all requests */
 void fuse_abort_conn(struct fuse_conn *fc);