hwmon: (adt7473) Remove unused defines

[linux-2.6-omap-h63xx.git] / fs / devpts / inode.c

diff --git a/fs/devpts/inode.c b/fs/devpts/inode.c
index f120e1207874715b052788ea9105458da9348145..285b64a8b06e125b1aee42a8317cfd0873d69f20 100644 (file)
--- a/fs/devpts/inode.c
+++ b/fs/devpts/inode.c
@@ -17,6 +17,8 @@
 #include <linux/namei.h>
 #include <linux/mount.h>
 #include <linux/tty.h>
+#include <linux/mutex.h>
+#include <linux/idr.h>
 #include <linux/devpts_fs.h>
 #include <linux/parser.h>
 #include <linux/fsnotify.h>
@@ -26,6 +28,10 @@
 
 #define DEVPTS_DEFAULT_MODE 0600
 
+extern int pty_limit;                  /* Config limit on Unix98 ptys */
+static DEFINE_IDR(allocated_ptys);
+static DEFINE_MUTEX(allocated_ptys_lock);
+
 static struct vfsmount *devpts_mnt;
 static struct dentry *devpts_root;
 
@@ -171,9 +177,44 @@ static struct dentry *get_node(int num)
        return lookup_one_len(s, root, sprintf(s, "%d", num));
 }
 
+int devpts_new_index(void)
+{
+       int index;
+       int idr_ret;
+
+retry:
+       if (!idr_pre_get(&allocated_ptys, GFP_KERNEL)) {
+               return -ENOMEM;
+       }
+
+       mutex_lock(&allocated_ptys_lock);
+       idr_ret = idr_get_new(&allocated_ptys, NULL, &index);
+       if (idr_ret < 0) {
+               mutex_unlock(&allocated_ptys_lock);
+               if (idr_ret == -EAGAIN)
+                       goto retry;
+               return -EIO;
+       }
+
+       if (index >= pty_limit) {
+               idr_remove(&allocated_ptys, index);
+               mutex_unlock(&allocated_ptys_lock);
+               return -EIO;
+       }
+       mutex_unlock(&allocated_ptys_lock);
+       return index;
+}
+
+void devpts_kill_index(int idx)
+{
+       mutex_lock(&allocated_ptys_lock);
+       idr_remove(&allocated_ptys, idx);
+       mutex_unlock(&allocated_ptys_lock);
+}
+
 int devpts_pty_new(struct tty_struct *tty)
 {
-       int number = tty->index;
+       int number = tty->index; /* tty layer puts index from devpts_new_index() in here */
        struct tty_driver *driver = tty->driver;
        dev_t device = MKDEV(driver->major, driver->minor_start+number);
        struct dentry *dentry;