Add /dev/btrfs-control for device scanning ioctls

Signed-off-by: Chris Mason <chris.mason@oracle.com>

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 5e392804ab15eec31925c4314f91d5db0c34a0e0..14eb8fc87015d7d25099ec1622fa648cf6d74162 100644 (file)
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -374,10 +374,6 @@ again:
                        found_group = cache;
                        goto found;
                }
-               if (full_search) {
-                       printk("failed on cache %Lu used %Lu total %Lu\n",
-                              cache->key.objectid, used, cache->key.offset);
-               }
                cond_resched();
        }
        if (!full_search) {

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 4423a91206a1a35a0e665c39d9d1e55f6ab531b8..67ed216df4755c750c3d27f4fe4259710f80ea67 100644 (file)
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -36,6 +36,7 @@
 #include <linux/parser.h>
 #include <linux/ctype.h>
 #include <linux/namei.h>
+#include <linux/miscdevice.h>
 #include "ctree.h"
 #include "disk-io.h"
 #include "transaction.h"
@@ -444,6 +445,13 @@ static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
        return 0;
 }
 
+static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
+                               unsigned long arg)
+{
+       printk("btrfs control ioctl %d\n", cmd);
+       return 0;
+}
+
 static struct file_system_type btrfs_fs_type = {
        .owner          = THIS_MODULE,
        .name           = "btrfs",
@@ -451,6 +459,7 @@ static struct file_system_type btrfs_fs_type = {
        .kill_sb        = kill_block_super,
        .fs_flags       = FS_REQUIRES_DEV,
 };
+
 static void btrfs_write_super_lockfs(struct super_block *sb)
 {
        struct btrfs_root *root = btrfs_sb(sb);
@@ -482,6 +491,30 @@ static struct super_operations btrfs_super_ops = {
        .write_super_lockfs = btrfs_write_super_lockfs,
        .unlockfs       = btrfs_unlockfs,
 };
+
+static const struct file_operations btrfs_ctl_fops = {
+       .unlocked_ioctl  = btrfs_control_ioctl,
+       .compat_ioctl = btrfs_control_ioctl,
+       .owner   = THIS_MODULE,
+};
+
+static struct miscdevice btrfs_misc = {
+       .minor          = MISC_DYNAMIC_MINOR,
+       .name           = "btrfs-control",
+       .fops           = &btrfs_ctl_fops
+};
+
+static int btrfs_interface_init(void)
+{
+       return misc_register(&btrfs_misc);
+}
+
+void btrfs_interface_exit(void)
+{
+       if (misc_deregister(&btrfs_misc) < 0)
+               printk("misc_deregister failed for control device");
+}
+
 static int __init init_btrfs_fs(void)
 {
        int err;
@@ -503,11 +536,16 @@ static int __init init_btrfs_fs(void)
        if (err)
                goto free_extent_io;
 
-       err = register_filesystem(&btrfs_fs_type);
+       err = btrfs_interface_init();
        if (err)
                goto free_extent_map;
+       err = register_filesystem(&btrfs_fs_type);
+       if (err)
+               goto unregister_ioctl;
        return 0;
 
+unregister_ioctl:
+       btrfs_interface_exit();
 free_extent_map:
        extent_map_exit();
 free_extent_io:
@@ -526,6 +564,7 @@ static void __exit exit_btrfs_fs(void)
        btrfs_destroy_cachep();
        extent_map_exit();
        extent_io_exit();
+       btrfs_interface_exit();
        unregister_filesystem(&btrfs_fs_type);
        btrfs_exit_sysfs();
 }