devpts: factor out PTY index allocation

[safe/jmp/linux-2.6] / drivers / char / tty_io.c

diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index edcb7e4..1d298c2 100644 (file)
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -91,7 +91,6 @@
 #include <linux/module.h>
 #include <linux/smp_lock.h>
 #include <linux/device.h>
-#include <linux/idr.h>
 #include <linux/wait.h>
 #include <linux/bitops.h>
 #include <linux/delay.h>
@@ -137,9 +136,6 @@ EXPORT_SYMBOL(tty_mutex);
 
 #ifdef CONFIG_UNIX98_PTYS
 extern struct tty_driver *ptm_driver;  /* Unix98 pty masters; for /dev/ptmx */
-extern int pty_limit;                  /* Config limit on Unix98 ptys */
-static DEFINE_IDR(allocated_ptys);
-static DEFINE_MUTEX(allocated_ptys_lock);
 static int ptmx_open(struct inode *, struct file *);
 #endif
 
@@ -2639,15 +2635,9 @@ static void release_dev(struct file *filp)
         */
        release_tty(tty, idx);
 
-#ifdef CONFIG_UNIX98_PTYS
        /* Make this pty number available for reallocation */
-       if (devpts) {
-               mutex_lock(&allocated_ptys_lock);
-               idr_remove(&allocated_ptys, idx);
-               mutex_unlock(&allocated_ptys_lock);
-       }
-#endif
-
+       if (devpts)
+               devpts_kill_index(idx);
 }
 
 /**
@@ -2803,29 +2793,13 @@ static int ptmx_open(struct inode *inode, struct file *filp)
        struct tty_struct *tty;
        int retval;
        int index;
-       int idr_ret;
 
        nonseekable_open(inode, filp);
 
        /* find a device that is not in use. */
-       mutex_lock(&allocated_ptys_lock);
-       if (!idr_pre_get(&allocated_ptys, GFP_KERNEL)) {
-               mutex_unlock(&allocated_ptys_lock);
-               return -ENOMEM;
-       }
-       idr_ret = idr_get_new(&allocated_ptys, NULL, &index);
-       if (idr_ret < 0) {
-               mutex_unlock(&allocated_ptys_lock);
-               if (idr_ret == -EAGAIN)
-                       return -ENOMEM;
-               return -EIO;
-       }
-       if (index >= pty_limit) {
-               idr_remove(&allocated_ptys, index);
-               mutex_unlock(&allocated_ptys_lock);
-               return -EIO;
-       }
-       mutex_unlock(&allocated_ptys_lock);
+       index = devpts_new_index();
+       if (index < 0)
+               return index;
 
        mutex_lock(&tty_mutex);
        retval = init_dev(ptm_driver, index, &tty);
@@ -2850,9 +2824,7 @@ out1:
        release_dev(filp);
        return retval;
 out:
-       mutex_lock(&allocated_ptys_lock);
-       idr_remove(&allocated_ptys, index);
-       mutex_unlock(&allocated_ptys_lock);
+       devpts_kill_index(index);
        return retval;
 }
 #endif