Merge git://git.infradead.org/mtd-2.6

[pandora-kernel.git] / fs / devpts / inode.c

diff --git a/fs/devpts/inode.c b/fs/devpts/inode.c
index 643e57b..488eb42 100644 (file)
--- a/fs/devpts/inode.c
+++ b/fs/devpts/inode.c
@@ -17,11 +17,21 @@
 #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>
+#include <linux/seq_file.h>
 
 #define DEVPTS_SUPER_MAGIC 0x1cd1
 
+#define DEVPTS_DEFAULT_MODE 0600
+
+extern int pty_limit;                  /* Config limit on Unix98 ptys */
+static DEFINE_IDA(allocated_ptys);
+static DEFINE_MUTEX(allocated_ptys_lock);
+
 static struct vfsmount *devpts_mnt;
 static struct dentry *devpts_root;
 
@@ -31,7 +41,7 @@ static struct {
        uid_t   uid;
        gid_t   gid;
        umode_t mode;
-} config = {.mode = 0600};
+} config = {.mode = DEVPTS_DEFAULT_MODE};
 
 enum {
        Opt_uid, Opt_gid, Opt_mode,
@@ -53,7 +63,7 @@ static int devpts_remount(struct super_block *sb, int *flags, char *data)
        config.setgid  = 0;
        config.uid     = 0;
        config.gid     = 0;
-       config.mode    = 0600;
+       config.mode    = DEVPTS_DEFAULT_MODE;
 
        while ((p = strsep(&data, ",")) != NULL) {
                substring_t args[MAX_OPT_ARGS];
@@ -80,7 +90,7 @@ static int devpts_remount(struct super_block *sb, int *flags, char *data)
                case Opt_mode:
                        if (match_octal(&args[0], &option))
                                return -EINVAL;
-                       config.mode = option & ~S_IFMT;
+                       config.mode = option & S_IALLUGO;
                        break;
                default:
                        printk(KERN_ERR "devpts: called with bogus options\n");
@@ -91,9 +101,21 @@ static int devpts_remount(struct super_block *sb, int *flags, char *data)
        return 0;
 }
 
+static int devpts_show_options(struct seq_file *seq, struct vfsmount *vfs)
+{
+       if (config.setuid)
+               seq_printf(seq, ",uid=%u", config.uid);
+       if (config.setgid)
+               seq_printf(seq, ",gid=%u", config.gid);
+       seq_printf(seq, ",mode=%03o", config.mode);
+
+       return 0;
+}
+
 static const struct super_operations devpts_sops = {
        .statfs         = simple_statfs,
        .remount_fs     = devpts_remount,
+       .show_options   = devpts_show_options,
 };
 
 static int
@@ -155,9 +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 ida_ret;
+
+retry:
+       if (!ida_pre_get(&allocated_ptys, GFP_KERNEL)) {
+               return -ENOMEM;
+       }
+
+       mutex_lock(&allocated_ptys_lock);
+       ida_ret = ida_get_new(&allocated_ptys, &index);
+       if (ida_ret < 0) {
+               mutex_unlock(&allocated_ptys_lock);
+               if (ida_ret == -EAGAIN)
+                       goto retry;
+               return -EIO;
+       }
+
+       if (index >= pty_limit) {
+               ida_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);
+       ida_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;
@@ -178,8 +235,10 @@ int devpts_pty_new(struct tty_struct *tty)
        inode->i_private = tty;
 
        dentry = get_node(number);
-       if (!IS_ERR(dentry) && !dentry->d_inode)
+       if (!IS_ERR(dentry) && !dentry->d_inode) {
                d_instantiate(dentry, inode);
+               fsnotify_create(devpts_root->d_inode, dentry);
+       }
 
        mutex_unlock(&devpts_root->d_inode->i_mutex);