From ba0ae447ef6da18b0677fe5fb27117cb1d28b30a Mon Sep 17 00:00:00 2001
From: itohy <itohy@NetBSD.org>
Date: Thu, 17 Feb 2000 03:06:12 +0000
Subject: [PATCH] Fix SIGINFO botch (PR #8868). Continue partial write(2) on
 signals (xwrite()). Partial read(2) at a few places are also continued
 (xread()).

Add {read,write}_with_restart() hooks for porting on systems
which don't restart interrupted read()/write() calls.

Reviewed and discussed in tech-kern and tech-userlevel lists.
---
 bin/pax/ar_io.c     | 144 +++++++++++++++++++++++++++++++++++++++++---
 bin/pax/buf_subs.c  |  10 +--
 bin/pax/extern.h    |  11 +++-
 bin/pax/file_subs.c |   8 +--
 bin/pax/tables.c    |  16 ++---
 5 files changed, 162 insertions(+), 27 deletions(-)

diff --git a/bin/pax/ar_io.c b/bin/pax/ar_io.c
index 83c504dab350..450614d29fed 100644
--- a/bin/pax/ar_io.c
+++ b/bin/pax/ar_io.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: ar_io.c,v 1.14 1999/10/22 20:59:08 is Exp $	*/
+/*	$NetBSD: ar_io.c,v 1.15 2000/02/17 03:06:12 itohy Exp $	*/
 
 /*-
  * Copyright (c) 1992 Keith Muller.
@@ -42,7 +42,7 @@
 #if 0
 static char sccsid[] = "@(#)ar_io.c	8.2 (Berkeley) 4/18/94";
 #else
-__RCSID("$NetBSD: ar_io.c,v 1.14 1999/10/22 20:59:08 is Exp $");
+__RCSID("$NetBSD: ar_io.c,v 1.15 2000/02/17 03:06:12 itohy Exp $");
 #endif
 #endif /* not lint */
 
@@ -438,7 +438,7 @@ ar_drain()
 	/*
 	 * keep reading until pipe is drained
 	 */
-	while ((res = read(arfd, drbuf, sizeof(drbuf))) > 0)
+	while ((res = read_with_restart(arfd, drbuf, sizeof(drbuf))) > 0)
 		;
 	lstrval = res;
 }
@@ -518,6 +518,132 @@ ar_app_ok()
 	return(-1);
 }
 
+#ifdef SYS_NO_RESTART
+/*
+ * read_with_restart()
+ *	Equivalent to read() but does retry on signals.
+ *	This function is not needed on 4.2BSD and later.
+ * Return:
+ *	Number of bytes written.  -1 indicates an error.
+ */
+
+#if __STDC__
+int
+read_with_restart(int fd, void *buf, int bsz)
+#else
+int
+read_with_restart(fd, buf, bsz)
+	int fd;
+	void *buf;
+	int bsz;
+#endif
+{
+	int r;
+
+	while (((r = read(fd, buf, bsz)) < 0) && errno == EINTR)
+		;
+
+	return(r);
+}
+#endif
+
+/*
+ * xread()
+ *	Equivalent to read() but does retry on partial read, which may occur
+ *	on signals.
+ * Return:
+ *	Number of bytes read.  0 for end of file, -1 for an error.
+ */
+
+#if __STDC__
+int
+xread(int fd, void *buf, int bsz)
+#else
+int
+xread(fd, buf, bsz)
+	int fd;
+	void *buf;
+	int bsz;
+#endif
+{
+	char *b = buf;
+	int nread = 0;
+	int r;
+
+	do {
+		if ((r = read_with_restart(fd, b, bsz)) <= 0)
+			break;
+		b += r;
+		bsz -= r;
+		nread += r;
+	} while (bsz > 0);
+
+	return(nread ? nread : r);
+}
+
+#ifdef SYS_NO_RESTART
+/*
+ * write_with_restart()
+ *	Equivalent to write() but does retry on signals.
+ *	This function is not needed on 4.2BSD and later.
+ * Return:
+ *	Number of bytes written.  -1 indicates an error.
+ */
+
+#if __STDC__
+int
+write_with_restart(int fd, void *buf, int bsz)
+#else
+int
+write_with_restart(fd, buf, bsz)
+	int fd;
+	void *buf;
+	int bsz;
+#endif
+{
+	int r;
+
+	while (((r = write(fd, buf, bsz)) < 0) && errno == EINTR)
+		;
+
+	return(r);
+}
+#endif
+
+/*
+ * xwrite()
+ *	Equivalent to write() but does retry on partial write, which may occur
+ *	on signals.
+ * Return:
+ *	Number of bytes written.  -1 indicates an error.
+ */
+
+#if __STDC__
+int
+xwrite(int fd, void *buf, int bsz)
+#else
+int
+xwrite(fd, buf, bsz)
+	int fd;
+	void *buf;
+	int bsz;
+#endif
+{
+	char *b = buf;
+	int written = 0;
+	int r;
+
+	do {
+		if ((r = write_with_restart(fd, b, bsz)) <= 0)
+			break;
+		b += r;
+		bsz -= r;
+		written += r;
+	} while (bsz > 0);
+
+	return(written ? written : r);
+}
+
 /*
  * ar_read()
  *	read up to a specified number of bytes from the archive into the
@@ -550,7 +676,7 @@ ar_read(buf, cnt)
 	 */
 	switch (artyp) {
 	case ISTAPE:
-		if ((res = read(arfd, buf, cnt)) > 0) {
+		if ((res = read_with_restart(arfd, buf, cnt)) > 0) {
 			/*
 			 * CAUTION: tape systems may not always return the same
 			 * sized records so we leave blksz == MAXBLK. The
@@ -588,7 +714,7 @@ ar_read(buf, cnt)
 		 * and return. Trying to do anything else with them runs the
 		 * risk of failure.
 		 */
-		if ((res = read(arfd, buf, cnt)) > 0) {
+		if ((res = read_with_restart(arfd, buf, cnt)) > 0) {
 			io_ok = 1;
 			return(res);
 		}
@@ -637,7 +763,7 @@ ar_write(buf, bsz)
 	if (lstrval <= 0)
 		return(lstrval);
 
-	if ((res = write(arfd, buf, bsz)) == bsz) {
+	if ((res = xwrite(arfd, buf, bsz)) == bsz) {
 		wr_trail = 1;
 		io_ok = 1;
 		return(bsz);
@@ -1064,7 +1190,7 @@ get_phys()
 		 * we know we are at file mark when we get back a 0 from
 		 * read()
 		 */
-		while ((res = read(arfd, scbuf, sizeof(scbuf))) > 0)
+		while ((res = read_with_restart(arfd, scbuf, sizeof(scbuf))) > 0)
 			padsz += res;
 		if (res < 0) {
 			syswarn(1, errno, "Unable to locate tape filemark.");
@@ -1093,7 +1219,7 @@ get_phys()
 		syswarn(1, errno, "Unable to backspace over last tape block.");
 		return(-1);
 	}
-	if ((phyblk = read(arfd, scbuf, sizeof(scbuf))) <= 0) {
+	if ((phyblk = read_with_restart(arfd, scbuf, sizeof(scbuf))) <= 0) {
 		syswarn(1, errno, "Cannot determine archive tape blocksize.");
 		return(-1);
 	}
@@ -1102,7 +1228,7 @@ get_phys()
 	 * read foward to the file mark, then back up in front of the filemark
 	 * (this is a bit paranoid, but should be safe to do).
 	 */
-	while ((res = read(arfd, scbuf, sizeof(scbuf))) > 0)
+	while ((res = read_with_restart(arfd, scbuf, sizeof(scbuf))) > 0)
 		;
 	if (res < 0) {
 		syswarn(1, errno, "Unable to locate tape filemark.");
diff --git a/bin/pax/buf_subs.c b/bin/pax/buf_subs.c
index 0aa1938b18d5..6c6fdd7b39c2 100644
--- a/bin/pax/buf_subs.c
+++ b/bin/pax/buf_subs.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: buf_subs.c,v 1.11 1999/10/22 10:43:11 mrg Exp $	*/
+/*	$NetBSD: buf_subs.c,v 1.12 2000/02/17 03:06:13 itohy Exp $	*/
 
 /*-
  * Copyright (c) 1992 Keith Muller.
@@ -42,7 +42,7 @@
 #if 0
 static char sccsid[] = "@(#)buf_subs.c	8.2 (Berkeley) 4/18/94";
 #else
-__RCSID("$NetBSD: buf_subs.c,v 1.11 1999/10/22 10:43:11 mrg Exp $");
+__RCSID("$NetBSD: buf_subs.c,v 1.12 2000/02/17 03:06:13 itohy Exp $");
 #endif
 #endif /* not lint */
 
@@ -699,7 +699,7 @@ wr_rdfile(arcn, ifd, left)
 			return(-1);
 		}
 		cnt = MIN(cnt, size);
-		if ((res = read(ifd, bufpt, cnt)) <= 0)
+		if ((res = read_with_restart(ifd, bufpt, cnt)) <= 0)
 			break;
 		size -= res;
 		bufpt += res;
@@ -884,10 +884,10 @@ cp_file(arcn, fd1, fd2)
 	 * read the source file and copy to destination file until EOF
 	 */
 	for(;;) {
-		if ((cnt = read(fd1, buf, blksz)) <= 0)
+		if ((cnt = read_with_restart(fd1, buf, blksz)) <= 0)
 			break;
 		if (no_hole)
-			res = write(fd2, buf, cnt);
+			res = xwrite(fd2, buf, cnt);
 		else
 			res = file_write(fd2, buf, cnt, &rem, &isem, sz, fnm);
 		if (res != cnt)
diff --git a/bin/pax/extern.h b/bin/pax/extern.h
index 742a0b0f4c3f..889959f4d811 100644
--- a/bin/pax/extern.h
+++ b/bin/pax/extern.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: extern.h,v 1.20 1999/11/01 01:35:58 mrg Exp $	*/
+/*	$NetBSD: extern.h,v 1.21 2000/02/17 03:06:13 itohy Exp $	*/
 
 /*-
  * Copyright (c) 1992 Keith Muller.
@@ -57,6 +57,15 @@ void ar_close __P((void));
 void ar_drain __P((void));
 int ar_set_wr __P((void));
 int ar_app_ok __P((void));
+#ifdef SYS_NO_RESTART
+int read_with_restart __P((int, void *, int));
+int write_with_restart __P((int, void *, int));
+#else
+#define read_with_restart	read
+#define write_with_restart	write
+#endif
+int xread __P((int, void *, int));
+int xwrite __P((int, void *, int));
 int ar_read __P((char *, int));
 int ar_write __P((char *, int));
 int ar_rdsync __P((void));
diff --git a/bin/pax/file_subs.c b/bin/pax/file_subs.c
index 4f89b42691fe..4f9ac38be670 100644
--- a/bin/pax/file_subs.c
+++ b/bin/pax/file_subs.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: file_subs.c,v 1.15 1999/11/07 15:48:24 mycroft Exp $	*/
+/*	$NetBSD: file_subs.c,v 1.16 2000/02/17 03:06:13 itohy Exp $	*/
 
 /*-
  * Copyright (c) 1992 Keith Muller.
@@ -42,7 +42,7 @@
 #if 0
 static char sccsid[] = "@(#)file_subs.c	8.1 (Berkeley) 5/31/93";
 #else
-__RCSID("$NetBSD: file_subs.c,v 1.15 1999/11/07 15:48:24 mycroft Exp $");
+__RCSID("$NetBSD: file_subs.c,v 1.16 2000/02/17 03:06:13 itohy Exp $");
 #endif
 #endif /* not lint */
 
@@ -948,7 +948,7 @@ file_write(fd, str, cnt, rem, isempt, sz, name)
 			}
 			strncpy(gnu_hack_string, st, wcnt);
 			gnu_hack_string[wcnt] = 0;
-		} else if (write(fd, st, wcnt) != wcnt) {
+		} else if (xwrite(fd, st, wcnt) != wcnt) {
 			syswarn(1, errno, "Failed write to file %s", name);
 			return(-1);
 		}
@@ -992,7 +992,7 @@ file_flush(fd, fname, isempt)
 		return;
 	}
 
-	if (write(fd, blnk, 1) < 0)
+	if (write_with_restart(fd, blnk, 1) < 0)
 		syswarn(1, errno, "Failed write to file %s", fname);
 	return;
 }
diff --git a/bin/pax/tables.c b/bin/pax/tables.c
index 91924d6a1b34..e671b3182558 100644
--- a/bin/pax/tables.c
+++ b/bin/pax/tables.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: tables.c,v 1.10 1999/11/01 01:35:59 mrg Exp $	*/
+/*	$NetBSD: tables.c,v 1.11 2000/02/17 03:06:13 itohy Exp $	*/
 
 /*-
  * Copyright (c) 1992 Keith Muller.
@@ -42,7 +42,7 @@
 #if 0
 static char sccsid[] = "@(#)tables.c	8.1 (Berkeley) 5/31/93";
 #else
-__RCSID("$NetBSD: tables.c,v 1.10 1999/11/01 01:35:59 mrg Exp $");
+__RCSID("$NetBSD: tables.c,v 1.11 2000/02/17 03:06:13 itohy Exp $");
 #endif
 #endif /* not lint */
 
@@ -446,7 +446,7 @@ chk_ftime(arcn)
 					    "Failed ftime table seek");
 					return(-1);
 				}
-				if (read(ffd, ckname, namelen) != namelen) {
+				if (xread(ffd, ckname, namelen) != namelen) {
 					syswarn(1, errno,
 					    "Failed ftime table read");
 					return(-1);
@@ -492,7 +492,7 @@ chk_ftime(arcn)
 		 * offset. add the file to the head of the hash chain
 		 */
 		if ((pt->seek = lseek(ffd, (off_t)0, SEEK_END)) >= 0) {
-			if (write(ffd, arcn->name, namelen) == namelen) {
+			if (xwrite(ffd, arcn->name, namelen) == namelen) {
 				pt->mtime = arcn->sb.st_mtime;
 				pt->namelen = namelen;
 				pt->fow = ftab[indx];
@@ -1288,8 +1288,8 @@ add_dir(name, nlen, psb, frc_mode)
 	dblk.atime = psb->st_atime;
 	dblk.fflags = psb->st_flags;
 	dblk.frc_mode = frc_mode;
-	if ((write(dirfd, name, dblk.nlen) == dblk.nlen) &&
-	    (write(dirfd, (char *)&dblk, sizeof(dblk)) == sizeof(dblk))) {
+	if ((xwrite(dirfd, name, dblk.nlen) == dblk.nlen) &&
+	    (xwrite(dirfd, (char *)&dblk, sizeof(dblk)) == sizeof(dblk))) {
 		++dircnt;
 		return;
 	}
@@ -1329,11 +1329,11 @@ proc_dir()
 		 */
 		if (lseek(dirfd, -((off_t)sizeof(dblk)), SEEK_CUR) < 0) 
 			break;
-		if (read(dirfd,(char *)&dblk, sizeof(dblk)) != sizeof(dblk))
+		if (xread(dirfd,(char *)&dblk, sizeof(dblk)) != sizeof(dblk))
 			break;
 		if (lseek(dirfd, dblk.npos, SEEK_SET) < 0) 
 			break;
-		if (read(dirfd, name, dblk.nlen) != dblk.nlen)
+		if (xread(dirfd, name, dblk.nlen) != dblk.nlen)
 			break;
 		if (lseek(dirfd, dblk.npos, SEEK_SET) < 0) 
 			break;