[PATCH] fuse: use a per-mount spinlock

Remove the global spinlock in favor of a per-mount one.

This patch is basically find & replace.  The difficult part has already been
done by the previous patch.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

fs/fuse/fuse_i.h

 /*
   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.
@@ -144,7 +144,7 @@ struct fuse_req {
 	/*
 	 * The following bitfields are either set once before the
 	 * request is queued or setting/clearing them is protected by
-	 * fuse_lock
+	 * fuse_conn->lock
 	 */
 
 	/** True if the request has reply */
@@ -213,6 +213,9 @@ 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;
 
@@ -351,21 +354,6 @@ static inline u64 get_node_id(struct inode *inode)
 /** Device operations */
 extern const 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
  */
@@ -490,7 +478,7 @@ 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_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);

fs/fuse/inode.c

 /*
   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.
@@ -22,7 +22,6 @@ MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
 MODULE_DESCRIPTION("Filesystem in Userspace");
 MODULE_LICENSE("GPL");
 
-spinlock_t fuse_lock;
 static kmem_cache_t *fuse_inode_cachep;
 static struct subsystem connections_subsys;
 
@@ -207,13 +206,14 @@ static void fuse_put_super(struct super_block *sb)
 
 	down_write(&fc->sbput_sem);
 	while (!list_empty(&fc->background))
-		fuse_release_background(list_entry(fc->background.next,
+		fuse_release_background(fc,
+					list_entry(fc->background.next,
 						   struct fuse_req, bg_entry));
 
-	spin_lock(&fuse_lock);
+	spin_lock(&fc->lock);
 	fc->mounted = 0;
 	fc->connected = 0;
-	spin_unlock(&fuse_lock);
+	spin_unlock(&fc->lock);
 	up_write(&fc->sbput_sem);
 	/* Flush all readers on this fs */
 	kill_fasync(&fc->fasync, SIGIO, POLL_IN);
@@ -388,6 +388,7 @@ static struct fuse_conn *new_conn(void)
 	fc = kzalloc(sizeof(*fc), GFP_KERNEL);
 	if (fc) {
 		int i;
+		spin_lock_init(&fc->lock);
 		init_waitqueue_head(&fc->waitq);
 		INIT_LIST_HEAD(&fc->pending);
 		INIT_LIST_HEAD(&fc->processing);
@@ -734,7 +735,6 @@ static int __init fuse_init(void)
 	printk("fuse init (API version %i.%i)\n",
 	       FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
 
-	spin_lock_init(&fuse_lock);
 	res = fuse_fs_init();
 	if (res)
 		goto err;