tty: Redo current tty locking

[safe/jmp/linux-2.6] / drivers / s390 / char / fs3270.c

diff --git a/drivers/s390/char/fs3270.c b/drivers/s390/char/fs3270.c
index ef004d0..84fbc90 100644 (file)
--- a/drivers/s390/char/fs3270.c
+++ b/drivers/s390/char/fs3270.c
@@ -14,21 +14,21 @@
 #include <linux/interrupt.h>
 #include <linux/list.h>
 #include <linux/types.h>
+#include <linux/smp_lock.h>
 
 #include <asm/ccwdev.h>
 #include <asm/cio.h>
-#include <asm/cpcmd.h>
 #include <asm/ebcdic.h>
 #include <asm/idals.h>
 
 #include "raw3270.h"
 #include "ctrlchar.h"
 
-struct raw3270_fn fs3270_fn;
+static struct raw3270_fn fs3270_fn;
 
 struct fs3270 {
        struct raw3270_view view;
-       pid_t fs_pid;                   /* Pid of controlling program. */
+       struct pid *fs_pid;             /* Pid of controlling program. */
        int read_command;               /* ccw command to use for reads. */
        int write_command;              /* ccw command to use for writes. */
        int attention;                  /* Got attention. */
@@ -103,7 +103,7 @@ fs3270_restore_callback(struct raw3270_request *rq, void *data)
        fp = (struct fs3270 *) rq->view;
        if (rq->rc != 0 || rq->rescnt != 0) {
                if (fp->fs_pid)
-                       kill_proc(fp->fs_pid, SIGHUP, 1);
+                       kill_pid(fp->fs_pid, SIGHUP, 1);
        }
        fp->rdbuf_size = 0;
        raw3270_request_reset(rq);
@@ -174,7 +174,7 @@ fs3270_save_callback(struct raw3270_request *rq, void *data)
         */
        if (rq->rc != 0 || rq->rescnt == 0) {
                if (fp->fs_pid)
-                       kill_proc(fp->fs_pid, SIGHUP, 1);
+                       kill_pid(fp->fs_pid, SIGHUP, 1);
                fp->rdbuf_size = 0;
        } else
                fp->rdbuf_size = fp->rdbuf->size - rq->rescnt;
@@ -217,17 +217,17 @@ static int
 fs3270_irq(struct fs3270 *fp, struct raw3270_request *rq, struct irb *irb)
 {
        /* Handle ATTN. Set indication and wake waiters for attention. */
-       if (irb->scsw.dstat & DEV_STAT_ATTENTION) {
+       if (irb->scsw.cmd.dstat & DEV_STAT_ATTENTION) {
                fp->attention = 1;
                wake_up(&fp->wait);
        }
 
        if (rq) {
-               if (irb->scsw.dstat & DEV_STAT_UNIT_CHECK)
+               if (irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK)
                        rq->rc = -EIO;
                else
                        /* Normal end. Copy residual count. */
-                       rq->rescnt = irb->scsw.count;
+                       rq->rescnt = irb->scsw.cmd.count;
        }
        return RAW3270_IO_DONE;
 }
@@ -402,7 +402,7 @@ fs3270_release(struct raw3270_view *view)
 }
 
 /* View to a 3270 device. Can be console, tty or fullscreen. */
-struct raw3270_fn fs3270_fn = {
+static struct raw3270_fn fs3270_fn = {
        .activate = fs3270_activate,
        .deactivate = fs3270_deactivate,
        .intv = (void *) fs3270_irq,
@@ -420,34 +420,45 @@ fs3270_open(struct inode *inode, struct file *filp)
        struct idal_buffer *ib;
        int minor, rc;
 
-       if (imajor(filp->f_dentry->d_inode) != IBM_FS3270_MAJOR)
+       if (imajor(filp->f_path.dentry->d_inode) != IBM_FS3270_MAJOR)
                return -ENODEV;
-       minor = iminor(filp->f_dentry->d_inode);
+       lock_kernel();
+       minor = iminor(filp->f_path.dentry->d_inode);
        /* Check for minor 0 multiplexer. */
        if (minor == 0) {
-               if (!current->signal->tty)
-                       return -ENODEV;
-               if (current->signal->tty->driver->major != IBM_TTY3270_MAJOR)
-                       return -ENODEV;
-               minor = current->signal->tty->index + RAW3270_FIRSTMINOR;
+               struct tty_struct *tty;
+               mutex_lock(&tty_mutex);
+               tty = get_current_tty();
+               if (!tty || tty->driver->major != IBM_TTY3270_MAJOR) {
+                       tty_kref_put(tty);
+                       mutex_unlock(&tty_mutex);
+                       rc = -ENODEV;
+                       goto out;
+               }
+               minor = tty->index + RAW3270_FIRSTMINOR;
+               tty_kref_put(tty);
+               mutex_unlock(&tty_mutex);
        }
        /* Check if some other program is already using fullscreen mode. */
        fp = (struct fs3270 *) raw3270_find_view(&fs3270_fn, minor);
        if (!IS_ERR(fp)) {
                raw3270_put_view(&fp->view);
-               return -EBUSY;
+               rc = -EBUSY;
+               goto out;
        }
        /* Allocate fullscreen view structure. */
        fp = fs3270_alloc_view();
-       if (IS_ERR(fp))
-               return PTR_ERR(fp);
+       if (IS_ERR(fp)) {
+               rc = PTR_ERR(fp);
+               goto out;
+       }
 
        init_waitqueue_head(&fp->wait);
-       fp->fs_pid = current->pid;
+       fp->fs_pid = get_pid(task_pid(current));
        rc = raw3270_add_view(&fp->view, &fs3270_fn, minor);
        if (rc) {
                fs3270_free_view(&fp->view);
-               return rc;
+               goto out;
        }
 
        /* Allocate idal-buffer. */
@@ -455,7 +466,8 @@ fs3270_open(struct inode *inode, struct file *filp)
        if (IS_ERR(ib)) {
                raw3270_put_view(&fp->view);
                raw3270_del_view(&fp->view);
-               return PTR_ERR(fp);
+               rc = PTR_ERR(fp);
+               goto out;
        }
        fp->rdbuf = ib;
 
@@ -463,9 +475,11 @@ fs3270_open(struct inode *inode, struct file *filp)
        if (rc) {
                raw3270_put_view(&fp->view);
                raw3270_del_view(&fp->view);
-               return rc;
+               goto out;
        }
        filp->private_data = fp;
+out:
+       unlock_kernel();
        return 0;
 }
 
@@ -481,7 +495,8 @@ fs3270_close(struct inode *inode, struct file *filp)
        fp = filp->private_data;
        filp->private_data = NULL;
        if (fp) {
-               fp->fs_pid = 0;
+               put_pid(fp->fs_pid);
+               fp->fs_pid = NULL;
                raw3270_reset(&fp->view);
                raw3270_put_view(&fp->view);
                raw3270_del_view(&fp->view);
@@ -489,7 +504,7 @@ fs3270_close(struct inode *inode, struct file *filp)
        return 0;
 }
 
-static struct file_operations fs3270_fops = {
+static const struct file_operations fs3270_fops = {
        .owner           = THIS_MODULE,         /* owner */
        .read            = fs3270_read,         /* read */
        .write           = fs3270_write,        /* write */
@@ -508,11 +523,8 @@ fs3270_init(void)
        int rc;
 
        rc = register_chrdev(IBM_FS3270_MAJOR, "fs3270", &fs3270_fops);
-       if (rc) {
-               printk(KERN_ERR "fs3270 can't get major number %d: errno %d\n",
-                      IBM_FS3270_MAJOR, rc);
+       if (rc)
                return rc;
-       }
        return 0;
 }