diff options
| -rw-r--r-- | drivers/char/tty_io.c | 40 | ||||
| -rw-r--r-- | fs/devpts/inode.c | 43 | ||||
| -rw-r--r-- | include/linux/devpts_fs.h | 4 |
3 files changed, 52 insertions, 35 deletions
diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c index edcb7e471f0..1d298c2cf93 100644 --- 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 diff --git a/fs/devpts/inode.c b/fs/devpts/inode.c index f120e120787..285b64a8b06 100644 --- 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; diff --git a/include/linux/devpts_fs.h b/include/linux/devpts_fs.h index b672ddc0073..154769cad3f 100644 --- a/include/linux/devpts_fs.h +++ b/include/linux/devpts_fs.h @@ -17,6 +17,8 @@ #ifdef CONFIG_UNIX98_PTYS +int devpts_new_index(void); +void devpts_kill_index(int idx); int devpts_pty_new(struct tty_struct *tty); /* mknod in devpts */ struct tty_struct *devpts_get_tty(int number); /* get tty structure */ void devpts_pty_kill(int number); /* unlink */ @@ -24,6 +26,8 @@ void devpts_pty_kill(int number); /* unlink */ #else /* Dummy stubs in the no-pty case */ +static inline int devpts_new_index(void) { return -EINVAL; } +static inline void devpts_kill_index(int idx) { } static inline int devpts_pty_new(struct tty_struct *tty) { return -EINVAL; } static inline struct tty_struct *devpts_get_tty(int number) { return NULL; } static inline void devpts_pty_kill(int number) { } |