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Fixed data loss in writes to pty masters. Data was almost always lost

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at the end of each write for writes of more than 1K.

Fixed handling of residual count for early returns in writes to pty masters.
It was only adjusted in 2 out of 6 cases.

Added prototypes.
This commit is contained in:
bde 1995-10-25 18:23:58 +00:00
parent fcc3ae3084
commit 54ab2d9289
1 changed files with 23 additions and 8 deletions
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31
sys/kern/tty_pty.c
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@ -31,7 +31,7 @@
* SUCH DAMAGE.
*
* @(#)tty_pty.c 8.2 (Berkeley) 9/23/93
* $Id: tty_pty.c,v 1.20 1995/09/08 11:08:38 bde Exp $
* $Id: tty_pty.c,v 1.21 1995/09/19 12:26:47 bde Exp $
*/
/*
@ -52,6 +52,10 @@
#include <sys/vnode.h>
#include <sys/signalvar.h>
void ptyattach __P((int n));
void ptsstart __P((struct tty *tp));
void ptcwakeup __P((struct tty *tp, int flag));
#if NPTY == 1
#undef NPTY
#define NPTY 32 /* crude XXX */
@ -486,7 +490,8 @@ again:
if (pti->pt_flags & PF_REMOTE) {
if (tp->t_canq.c_cc)
goto block;
while (uio->uio_resid > 0 && tp->t_canq.c_cc < TTYHOG - 1) {
while ((uio->uio_resid > 0 || cc > 0) &&
tp->t_canq.c_cc < TTYHOG - 1) {
if (cc == 0) {
cc = min(uio->uio_resid, BUFSIZ);
cc = min(cc, TTYHOG - 1 - tp->t_canq.c_cc);
@ -495,19 +500,23 @@ again:
if (error)
return (error);
/* check again for safety */
if ((tp->t_state&TS_ISOPEN) == 0)
if ((tp->t_state & TS_ISOPEN) == 0) {
/* adjust as usual */
uio->uio_resid += cc;
return (EIO);
}
}
if (cc)
(void) b_to_q((char *)cp, cc, &tp->t_canq);
cc = 0;
cc -= b_to_q((char *)cp, cc, &tp->t_canq);
}
/* adjust for data copied in but not written */
uio->uio_resid += cc;
(void) putc(0, &tp->t_canq);
ttwakeup(tp);
wakeup(TSA_PTS_READ(tp));
return (0);
}
while (uio->uio_resid > 0) {
while (uio->uio_resid > 0 || cc > 0) {
if (cc == 0) {
cc = min(uio->uio_resid, BUFSIZ);
cp = locbuf;
@ -515,8 +524,11 @@ again:
if (error)
return (error);
/* check again for safety */
if ((tp->t_state&TS_ISOPEN) == 0)
if ((tp->t_state & TS_ISOPEN) == 0) {
/* adjust for data copied in but not written */
uio->uio_resid += cc;
return (EIO);
}
}
while (cc > 0) {
if ((tp->t_rawq.c_cc + tp->t_canq.c_cc) >= TTYHOG - 2 &&
@ -536,8 +548,11 @@ block:
* Come here to wait for slave to open, for space
* in outq, or space in rawq.
*/
if ((tp->t_state & TS_CONNECTED) == 0)
if ((tp->t_state & TS_CONNECTED) == 0) {
/* adjust for data copied in but not written */
uio->uio_resid += cc;
return (EIO);
}
if (flag & IO_NDELAY) {
/* adjust for data copied in but not written */
uio->uio_resid += cc;