[patch 20/22] fuse: make dirty stats available

[Miklos Szeredi <miklos@szeredi.hu>]

[-- Attachment #1: fuse_queue_stats.patch --]
[-- Type: text/plain, Size: 3840 bytes --]

From: Miklos Szeredi <mszeredi@suse.cz>

Make per-filesystem statistics about dirty and under-writeback pages
available through the fuse control filesystem.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
---

Index: linux/fs/fuse/control.c
===================================================================
--- linux.orig/fs/fuse/control.c	2007-02-27 14:40:54.000000000 +0100
+++ linux/fs/fuse/control.c	2007-02-27 14:41:13.000000000 +0100
@@ -41,24 +41,60 @@ static ssize_t fuse_conn_abort_write(str
 	return count;
 }
 
-static ssize_t fuse_conn_waiting_read(struct file *file, char __user *buf,
-				      size_t len, loff_t *ppos)
+enum fusectl_type {
+	FUSECTL_WAITING,
+	FUSECTL_NR_DIRTY,
+	FUSECTL_NR_WRITEBACK
+};
+
+static ssize_t fuse_conn_read(struct file *file, char __user *buf,
+			      size_t len, loff_t *ppos, enum fusectl_type sel)
 {
 	char tmp[32];
 	size_t size;
 
 	if (!*ppos) {
+		long val = 0;
 		struct fuse_conn *fc = fuse_ctl_file_conn_get(file);
 		if (!fc)
 			return 0;
 
-		file->private_data=(void *)(long)atomic_read(&fc->num_waiting);
+		switch (sel) {
+		case FUSECTL_WAITING:
+			val = atomic_read(&fc->num_waiting);
+			break;
+		case FUSECTL_NR_DIRTY:
+			val = atomic_long_read(&fc->bdi.nr_dirty);
+			break;
+		case FUSECTL_NR_WRITEBACK:
+			val = atomic_long_read(&fc->bdi.nr_writeback);
+			break;
+		}
+		file->private_data = (void *) val;
 		fuse_conn_put(fc);
 	}
 	size = sprintf(tmp, "%ld\n", (long)file->private_data);
 	return simple_read_from_buffer(buf, len, ppos, tmp, size);
 }
 
+static ssize_t fuse_conn_waiting_read(struct file *file, char __user *buf,
+				      size_t len, loff_t *ppos)
+{
+	return fuse_conn_read(file, buf, len, ppos, FUSECTL_WAITING);
+}
+
+static ssize_t fuse_conn_nr_dirty_read(struct file *file, char __user *buf,
+				       size_t len, loff_t *ppos)
+{
+	return fuse_conn_read(file, buf, len, ppos, FUSECTL_NR_DIRTY);
+}
+
+static ssize_t fuse_conn_nr_writeback_read(struct file *file, char __user *buf,
+					   size_t len, loff_t *ppos)
+{
+	return fuse_conn_read(file, buf, len, ppos, FUSECTL_NR_WRITEBACK);
+}
+
 static const struct file_operations fuse_ctl_abort_ops = {
 	.open = nonseekable_open,
 	.write = fuse_conn_abort_write,
@@ -69,6 +105,16 @@ static const struct file_operations fuse
 	.read = fuse_conn_waiting_read,
 };
 
+static const struct file_operations fuse_ctl_nr_dirty_ops = {
+	.open = nonseekable_open,
+	.read = fuse_conn_nr_dirty_read,
+};
+
+static const struct file_operations fuse_ctl_nr_writeback_ops = {
+	.open = nonseekable_open,
+	.read = fuse_conn_nr_writeback_read,
+};
+
 static struct dentry *fuse_ctl_add_dentry(struct dentry *parent,
 					  struct fuse_conn *fc,
 					  const char *name,
@@ -127,7 +173,11 @@ int fuse_ctl_add_conn(struct fuse_conn *
 	if (!fuse_ctl_add_dentry(parent, fc, "waiting", S_IFREG | 0400, 1,
 				NULL, &fuse_ctl_waiting_ops) ||
 	    !fuse_ctl_add_dentry(parent, fc, "abort", S_IFREG | 0200, 1,
-				 NULL, &fuse_ctl_abort_ops))
+				 NULL, &fuse_ctl_abort_ops) ||
+	    !fuse_ctl_add_dentry(parent, fc, "nr_dirty", S_IFREG | 0444, 1,
+				 NULL, &fuse_ctl_nr_dirty_ops) ||
+	    !fuse_ctl_add_dentry(parent, fc, "nr_writeback", S_IFREG | 0444, 1,
+				 NULL, &fuse_ctl_nr_writeback_ops))
 		goto err;
 
 	return 0;
Index: linux/fs/fuse/fuse_i.h
===================================================================
--- linux.orig/fs/fuse/fuse_i.h	2007-02-27 14:41:11.000000000 +0100
+++ linux/fs/fuse/fuse_i.h	2007-02-27 14:41:13.000000000 +0100
@@ -30,7 +30,7 @@
 #define FUSE_NAME_MAX 1024
 
 /** Number of dentries for each connection in the control filesystem */
-#define FUSE_CTL_NUM_DENTRIES 3
+#define FUSE_CTL_NUM_DENTRIES 5
 
 /** If the FUSE_DEFAULT_PERMISSIONS flag is given, the filesystem
     module will check permissions based on the file mode.  Otherwise no

--