lkml.org 
[lkml]   [2009]   [Jul]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
SubjectRe: [PATCH] kdesu broken
Date
Alan Cox <alan@lxorguk.ukuu.org.uk> writes:

>> And if it's right, unfortunately, I guess we can't return -EAGAIN in
>> this case to preserve behavior.
>
> To avoid the EAGAIN the close needs to block until all queued I/O has
> been processed by the ldisc the other end. That's not standards
> guaranteed or even what happens with a non pty port, but it is doable
> unless you take signals - we can't block signals or it can all deadlock.

Just a quick hack though. Is this wrong/unpreferable way?

n_tty_read() checks the pending buffer and consume it before
input_available_p().

Thanks.
--
OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>



Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
---
drivers/char/n_tty.c | 1 +
drivers/char/pty.c | 1 -
drivers/char/tty_buffer.c | 7 +++++--
include/linux/tty.h | 1 +
4 files changed, 7 insertions(+), 3 deletions(-)
diff -puN drivers/char/pty.c~pty-fixes4-fix2 drivers/char/pty.c
--- linux-2.6/drivers/char/pty.c~pty-fixes4-fix2 2009-07-28 05:00:45.000000000 +0900
+++ linux-2.6-hirofumi/drivers/char/pty.c 2009-07-28 05:00:48.000000000 +0900
@@ -64,7 +64,6 @@ static void pty_close(struct tty_struct
set_bit(TTY_EOFPENDING, &pair->flags);
set_bit(TTY_OTHER_CLOSED, &pair->flags);
spin_unlock_irqrestore(&pair->buf.lock, flags);
- tty_flip_buffer_push(pair);
wake_up_interruptible(&pair->read_wait);
wake_up_interruptible(&pair->write_wait);
if (tty->driver->subtype == PTY_TYPE_MASTER) {
diff -puN drivers/char/n_tty.c~pty-fixes4-fix2 drivers/char/n_tty.c
--- linux-2.6/drivers/char/n_tty.c~pty-fixes4-fix2 2009-07-28 05:01:10.000000000 +0900
+++ linux-2.6-hirofumi/drivers/char/n_tty.c 2009-07-28 05:07:49.000000000 +0900
@@ -1776,6 +1776,7 @@ do_it_again:
((minimum - (b - buf)) >= 1))
tty->minimum_to_wake = (minimum - (b - buf));

+ tty_flush_to_ldisc(tty);
if (!input_available_p(tty, 0)) {
if (test_bit(TTY_EOF, &tty->flags)) {
/* PTY pair closed and all data consumed */
diff -puN include/linux/tty.h~pty-fixes4-fix2 include/linux/tty.h
--- linux-2.6/include/linux/tty.h~pty-fixes4-fix2 2009-07-28 05:07:07.000000000 +0900
+++ linux-2.6-hirofumi/include/linux/tty.h 2009-07-28 05:07:30.000000000 +0900
@@ -396,6 +396,7 @@ extern void __do_SAK(struct tty_struct *
extern void disassociate_ctty(int priv);
extern void no_tty(void);
extern void tty_flip_buffer_push(struct tty_struct *tty);
+extern void tty_flush_to_ldisc(struct tty_struct *tty);
extern void tty_buffer_free_all(struct tty_struct *tty);
extern void tty_buffer_flush(struct tty_struct *tty);
extern void tty_buffer_init(struct tty_struct *tty);
diff -puN drivers/char/tty_buffer.c~pty-fixes4-fix2 drivers/char/tty_buffer.c
--- linux-2.6/drivers/char/tty_buffer.c~pty-fixes4-fix2 2009-07-28 05:41:12.000000000 +0900
+++ linux-2.6-hirofumi/drivers/char/tty_buffer.c 2009-07-28 14:24:48.000000000 +0900
@@ -388,8 +388,6 @@ int tty_prepare_flip_string_flags(struct
}
EXPORT_SYMBOL_GPL(tty_prepare_flip_string_flags);

-
-
/**
* flush_to_ldisc
* @work: tty structure passed from work queue.
@@ -473,6 +471,11 @@ static void flush_to_ldisc(struct work_s
tty_ldisc_deref(disc);
}

+void tty_flush_to_ldisc(struct tty_struct *tty)
+{
+ flush_to_ldisc(&tty->buf.work.work);
+}
+
/**
* tty_flip_buffer_push - terminal
* @tty: tty to push
_

\
 
 \ /
  Last update: 2009-07-28 07:37    [from the cache]
©2003-2011 Jasper Spaans