tty: remove resize window special case

This moves it to being a tty operation. That removes special cases and now
also means that resize can be picked up by um and other non vt consoles
which may have a resize operation.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 62 insertions, 20 deletions

diff --git a/drivers/char/vt.c b/drivers/char/vt.c
index 1bc00c9d860d..60359c360912 100644
--- a/drivers/char/vt.c
+++ b/drivers/char/vt.c
@@ -803,7 +803,25 @@ static inline int resize_screen(struct vc_data *vc, int width, int height,
  */
 #define VC_RESIZE_MAXCOL (32767)
 #define VC_RESIZE_MAXROW (32767)
-int vc_resize(struct vc_data *vc, unsigned int cols, unsigned int lines)
+
+/**
+ *      vc_do_resize    -       resizing method for the tty
+ *      @tty: tty being resized
+ *      @real_tty: real tty (different to tty if a pty/tty pair)
+ *      @vc: virtual console private data
+ *      @cols: columns
+ *      @lines: lines
+ *
+ *      Resize a virtual console, clipping according to the actual constraints.
+ *      If the caller passes a tty structure then update the termios winsize
+ *      information and perform any neccessary signal handling.
+ *
+ *      Caller must hold the console semaphore. Takes the termios mutex and
+ *      ctrl_lock of the tty IFF a tty is passed.
+ */
+
+static int vc_do_resize(struct tty_struct *tty, struct tty_struct *real_tty,
+                struct vc_data *vc, unsigned int cols, unsigned int lines)
 {
         unsigned long old_origin, new_origin, new_scr_end, rlth, rrem, err = 0;
         unsigned int old_cols, old_rows, old_row_size, old_screen_size;
@@ -907,24 +925,15 @@ int vc_resize(struct vc_data *vc, unsigned int cols, unsigned int lines)
         gotoxy(vc, vc->vc_x, vc->vc_y);
         save_cur(vc);
 
-        if (vc->vc_tty) {
-                struct winsize ws, *cws = &vc->vc_tty->winsize;
-                struct pid *pgrp = NULL;
-
+        if (tty) {
+                /* Rewrite the requested winsize data with the actual
+                   resulting sizes */
+                struct winsize ws;
                 memset(&ws, 0, sizeof(ws));
                 ws.ws_row = vc->vc_rows;
                 ws.ws_col = vc->vc_cols;
                 ws.ws_ypixel = vc->vc_scan_lines;
-
-                spin_lock_irq(&vc->vc_tty->ctrl_lock);
-                if ((ws.ws_row != cws->ws_row || ws.ws_col != cws->ws_col))
-                        pgrp = get_pid(vc->vc_tty->pgrp);
-                spin_unlock_irq(&vc->vc_tty->ctrl_lock);
-                if (pgrp) {
-                        kill_pgrp(vc->vc_tty->pgrp, SIGWINCH, 1);
-                        put_pid(pgrp);
-                }
-                *cws = ws;
+                tty_do_resize(tty, real_tty, &ws);
         }
 
         if (CON_IS_VISIBLE(vc))
@@ -932,14 +941,47 @@ int vc_resize(struct vc_data *vc, unsigned int cols, unsigned int lines)
         return err;
 }
 
-int vc_lock_resize(struct vc_data *vc, unsigned int cols, unsigned int lines)
+/**
+ *      vc_resize               -       resize a VT
+ *      @vc: virtual console
+ *      @cols: columns
+ *      @rows: rows
+ *
+ *      Resize a virtual console as seen from the console end of things. We
+ *      use the common vc_do_resize methods to update the structures. The
+ *      caller must hold the console sem to protect console internals and
+ *      vc->vc_tty
+ */
+
+int vc_resize(struct vc_data *vc, unsigned int cols, unsigned int rows)
+{
+        return vc_do_resize(vc->vc_tty, vc->vc_tty, vc, cols, rows);
+}
+
+/**
+ *      vt_resize               -       resize a VT
+ *      @tty: tty to resize
+ *      @real_tty: tty if a pty/tty pair
+ *      @ws: winsize attributes
+ *
+ *      Resize a virtual terminal. This is called by the tty layer as we
+ *      register our own handler for resizing. The mutual helper does all
+ *      the actual work.
+ *
+ *      Takes the console sem and the called methods then take the tty
+ *      termios_mutex and the tty ctrl_lock in that order.
+ */
+
+int vt_resize(struct tty_struct *tty, struct tty_struct *real_tty,
+        struct winsize *ws)
 {
-        int rc;
+        struct vc_data *vc = tty->driver_data;
+        int ret;
 
         acquire_console_sem();
-        rc = vc_resize(vc, cols, lines);
+        ret = vc_do_resize(tty, real_tty, vc, ws->ws_col, ws->ws_row);
         release_console_sem();
-        return rc;
+        return ret;
 }
 
 void vc_deallocate(unsigned int currcons)
@@ -2907,6 +2949,7 @@ static const struct tty_operations con_ops = {
         .start = con_start,
         .throttle = con_throttle,
         .unthrottle = con_unthrottle,
+        .resize = vt_resize,
 };
 
 int __init vty_init(void)
@@ -4061,7 +4104,6 @@ EXPORT_SYMBOL(default_blu);
 EXPORT_SYMBOL(update_region);
 EXPORT_SYMBOL(redraw_screen);
 EXPORT_SYMBOL(vc_resize);
-EXPORT_SYMBOL(vc_lock_resize);
 EXPORT_SYMBOL(fg_console);
 EXPORT_SYMBOL(console_blank_hook);
 EXPORT_SYMBOL(console_blanked);