From: Miklos Szeredi <miklos@szeredi.hu>

This patch adds the 'waiting' attribute which indicates how many filesystem
requests are currently waiting to be completed.  A non-zero value without any
filesystem activity indicates a hung or deadlocked filesystem.

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---

 fs/fuse/dev.c    |   12 +++++++++---
 fs/fuse/fuse_i.h |    3 +++
 fs/fuse/inode.c  |    9 +++++++++
 3 files changed, 21 insertions(+), 3 deletions(-)

diff -puN fs/fuse/dev.c~fuse-add-number-of-waiting-requests-attribute fs/fuse/dev.c
--- 25/fs/fuse/dev.c~fuse-add-number-of-waiting-requests-attribute	Fri Jan 13 17:35:56 2006
+++ 25-akpm/fs/fuse/dev.c	Fri Jan 13 17:35:56 2006
@@ -109,18 +109,24 @@ struct fuse_req *fuse_get_request(struct
 	int intr;
 	sigset_t oldset;
 
+	atomic_inc(&fc->num_waiting);
 	block_sigs(&oldset);
 	intr = down_interruptible(&fc->outstanding_sem);
 	restore_sigs(&oldset);
-	return intr ? NULL : do_get_request(fc);
+	if (intr) {
+		atomic_dec(&fc->num_waiting);
+		return NULL;
+	}
+	return do_get_request(fc);
 }
 
 static void fuse_putback_request(struct fuse_conn *fc, struct fuse_req *req)
 {
 	spin_lock(&fuse_lock);
-	if (req->preallocated)
+	if (req->preallocated) {
+		atomic_dec(&fc->num_waiting);
 		list_add(&req->list, &fc->unused_list);
-	else
+	} else
 		fuse_request_free(req);
 
 	/* If we are in debt decrease that first */
diff -puN fs/fuse/fuse_i.h~fuse-add-number-of-waiting-requests-attribute fs/fuse/fuse_i.h
--- 25/fs/fuse/fuse_i.h~fuse-add-number-of-waiting-requests-attribute	Fri Jan 13 17:35:56 2006
+++ 25-akpm/fs/fuse/fuse_i.h	Fri Jan 13 17:35:56 2006
@@ -280,6 +280,9 @@ struct fuse_conn {
 	/** 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;
 
diff -puN fs/fuse/inode.c~fuse-add-number-of-waiting-requests-attribute fs/fuse/inode.c
--- 25/fs/fuse/inode.c~fuse-add-number-of-waiting-requests-attribute	Fri Jan 13 17:35:56 2006
+++ 25-akpm/fs/fuse/inode.c	Fri Jan 13 17:35:56 2006
@@ -555,7 +555,16 @@ static struct file_system_type fuse_fs_t
 	.kill_sb	= kill_anon_super,
 };
 
+static ssize_t fuse_conn_waiting_show(struct fuse_conn *fc, char *page)
+{
+	return sprintf(page, "%i\n", atomic_read(&fc->num_waiting));
+}
+
+static struct fuse_conn_attr fuse_conn_waiting =
+	__ATTR(waiting, 0400, fuse_conn_waiting_show, NULL);
+
 static struct attribute *fuse_conn_attrs[] = {
+	&fuse_conn_waiting.attr,
 	NULL,
 };
 
_