mm/backing-dev.c: remove recently-added WARN_ON()

[pandora-kernel.git] / mm / backing-dev.c

diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index 08361b6..801c08b 100644 (file)
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -10,6 +10,80 @@
 
 static struct class *bdi_class;
 
+#ifdef CONFIG_DEBUG_FS
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+
+static struct dentry *bdi_debug_root;
+
+static void bdi_debug_init(void)
+{
+       bdi_debug_root = debugfs_create_dir("bdi", NULL);
+}
+
+static int bdi_debug_stats_show(struct seq_file *m, void *v)
+{
+       struct backing_dev_info *bdi = m->private;
+       long background_thresh;
+       long dirty_thresh;
+       long bdi_thresh;
+
+       get_dirty_limits(&background_thresh, &dirty_thresh, &bdi_thresh, bdi);
+
+#define K(x) ((x) << (PAGE_SHIFT - 10))
+       seq_printf(m,
+                  "BdiWriteback:     %8lu kB\n"
+                  "BdiReclaimable:   %8lu kB\n"
+                  "BdiDirtyThresh:   %8lu kB\n"
+                  "DirtyThresh:      %8lu kB\n"
+                  "BackgroundThresh: %8lu kB\n",
+                  (unsigned long) K(bdi_stat(bdi, BDI_WRITEBACK)),
+                  (unsigned long) K(bdi_stat(bdi, BDI_RECLAIMABLE)),
+                  K(bdi_thresh),
+                  K(dirty_thresh),
+                  K(background_thresh));
+#undef K
+
+       return 0;
+}
+
+static int bdi_debug_stats_open(struct inode *inode, struct file *file)
+{
+       return single_open(file, bdi_debug_stats_show, inode->i_private);
+}
+
+static const struct file_operations bdi_debug_stats_fops = {
+       .open           = bdi_debug_stats_open,
+       .read           = seq_read,
+       .llseek         = seq_lseek,
+       .release        = single_release,
+};
+
+static void bdi_debug_register(struct backing_dev_info *bdi, const char *name)
+{
+       bdi->debug_dir = debugfs_create_dir(name, bdi_debug_root);
+       bdi->debug_stats = debugfs_create_file("stats", 0444, bdi->debug_dir,
+                                              bdi, &bdi_debug_stats_fops);
+}
+
+static void bdi_debug_unregister(struct backing_dev_info *bdi)
+{
+       debugfs_remove(bdi->debug_stats);
+       debugfs_remove(bdi->debug_dir);
+}
+#else
+static inline void bdi_debug_init(void)
+{
+}
+static inline void bdi_debug_register(struct backing_dev_info *bdi,
+                                     const char *name)
+{
+}
+static inline void bdi_debug_unregister(struct backing_dev_info *bdi)
+{
+}
+#endif
+
 static ssize_t read_ahead_kb_store(struct device *dev,
                                  struct device_attribute *attr,
                                  const char *buf, size_t count)
@@ -40,21 +114,6 @@ static ssize_t name##_show(struct device *dev,                              \
 
 BDI_SHOW(read_ahead_kb, K(bdi->ra_pages))
 
-BDI_SHOW(reclaimable_kb, K(bdi_stat(bdi, BDI_RECLAIMABLE)))
-BDI_SHOW(writeback_kb, K(bdi_stat(bdi, BDI_WRITEBACK)))
-
-static inline unsigned long get_dirty(struct backing_dev_info *bdi, int i)
-{
-       unsigned long thresh[3];
-
-       get_dirty_limits(&thresh[0], &thresh[1], &thresh[2], bdi);
-
-       return thresh[i];
-}
-
-BDI_SHOW(dirty_kb, K(get_dirty(bdi, 1)))
-BDI_SHOW(bdi_dirty_kb, K(get_dirty(bdi, 2)))
-
 static ssize_t min_ratio_store(struct device *dev,
                struct device_attribute *attr, const char *buf, size_t count)
 {
@@ -95,10 +154,6 @@ BDI_SHOW(max_ratio, bdi->max_ratio)
 
 static struct device_attribute bdi_dev_attrs[] = {
        __ATTR_RW(read_ahead_kb),
-       __ATTR_RO(reclaimable_kb),
-       __ATTR_RO(writeback_kb),
-       __ATTR_RO(dirty_kb),
-       __ATTR_RO(bdi_dirty_kb),
        __ATTR_RW(min_ratio),
        __ATTR_RW(max_ratio),
        __ATTR_NULL,
@@ -108,37 +163,34 @@ static __init int bdi_class_init(void)
 {
        bdi_class = class_create(THIS_MODULE, "bdi");
        bdi_class->dev_attrs = bdi_dev_attrs;
+       bdi_debug_init();
        return 0;
 }
 
-core_initcall(bdi_class_init);
+postcore_initcall(bdi_class_init);
 
 int bdi_register(struct backing_dev_info *bdi, struct device *parent,
                const char *fmt, ...)
 {
-       char *name;
        va_list args;
        int ret = 0;
        struct device *dev;
 
+       if (bdi->dev)   /* The driver needs to use separate queues per device */
+               goto exit;
+
        va_start(args, fmt);
-       name = kvasprintf(GFP_KERNEL, fmt, args);
+       dev = device_create_vargs(bdi_class, parent, MKDEV(0, 0), bdi, fmt, args);
        va_end(args);
-
-       if (!name)
-               return -ENOMEM;
-
-       dev = device_create(bdi_class, parent, MKDEV(0, 0), name);
        if (IS_ERR(dev)) {
                ret = PTR_ERR(dev);
                goto exit;
        }
 
        bdi->dev = dev;
-       dev_set_drvdata(bdi->dev, bdi);
+       bdi_debug_register(bdi, dev_name(dev));
 
 exit:
-       kfree(name);
        return ret;
 }
 EXPORT_SYMBOL(bdi_register);
@@ -152,6 +204,7 @@ EXPORT_SYMBOL(bdi_register_dev);
 void bdi_unregister(struct backing_dev_info *bdi)
 {
        if (bdi->dev) {
+               bdi_debug_unregister(bdi);
                device_unregister(bdi->dev);
                bdi->dev = NULL;
        }