[lxc-devel] [lxc/master] "busy" field init to -1 instead of 0

[Rachid-Koucha on Github]

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From dd3de5683d8db869c962c23e9a48f57220888c2f Mon Sep 17 00:00:00 2001
From: Rachid Koucha <47061324+Rachid-Koucha at users.noreply.github.com>
Date: Fri, 6 Dec 2019 14:59:52 +0100
Subject: [PATCH 1/3] Init "busy" field to -1 as 0 is valid fd

"busy" field is assigned with the command socket descriptor when the terminal is in use. So, use "-1" to disable it.
Signed-off-by: Rachid Koucha <rachid.koucha at gmail.com>
---
 src/lxc/start.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/lxc/start.c b/src/lxc/start.c
index 6e2f0ab046..de564291f8 100644
--- a/src/lxc/start.c
+++ b/src/lxc/start.c
@@ -1526,11 +1526,11 @@ static int lxc_recv_ttys_from_child(struct lxc_handler *handler)
 			break;
 
 		tty = &ttys->tty[i];
-		tty->busy = 0;
+		tty->busy = -1;
 		tty->master = ttyfds[0];
 		tty->slave = ttyfds[1];
 		TRACE("Received pty with master fd %d and slave fd %d from "
-		      "parent", tty->master, tty->slave);
+		      "child", tty->master, tty->slave);
 	}
 
 	if (ret < 0)

From 7581d645eea3863b0df568b637b45e4a56349d3e Mon Sep 17 00:00:00 2001
From: Rachid Koucha <47061324+Rachid-Koucha at users.noreply.github.com>
Date: Fri, 6 Dec 2019 15:04:31 +0100
Subject: [PATCH 2/3] "busy" field set to 1 instead of 0

"busy" field is assigned with the command socket descriptor when the terminal is in use. So, use "-1" to disable it.

Signed-off-by: Rachid Koucha <rachid.koucha at gmail.com>
---
 src/lxc/conf.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/lxc/conf.c b/src/lxc/conf.c
index b192c7550a..03f4d69587 100644
--- a/src/lxc/conf.c
+++ b/src/lxc/conf.c
@@ -1006,7 +1006,7 @@ int lxc_allocate_ttys(struct lxc_conf *conf)
 			SYSWARN("Failed to set FD_CLOEXEC flag on slave fd %d of "
 			        "tty device \"%s\"", tty->slave, tty->name);
 
-		tty->busy = 0;
+		tty->busy = -1;
 	}
 
 	INFO("Finished creating %zu tty devices", ttys->max);

From 730aaf46e0397a5142e6515db733d68c64e4d88f Mon Sep 17 00:00:00 2001
From: Rachid Koucha <47061324+Rachid-Koucha at users.noreply.github.com>
Date: Fri, 6 Dec 2019 15:07:47 +0100
Subject: [PATCH 3/3] "busy" field set to -1 instead of 0

"busy" field is assigned with the command socket descriptor when the terminal is in use. So, use "-1" to disable it.

Signed-off-by: Rachid Koucha <rachid.koucha at gmail.com>
---
 src/lxc/terminal.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/lxc/terminal.c b/src/lxc/terminal.c
index aba8bb9217..26b2d50d7c 100644
--- a/src/lxc/terminal.c
+++ b/src/lxc/terminal.c
@@ -593,7 +593,7 @@ int lxc_terminal_allocate(struct lxc_conf *conf, int sockfd, int *ttyreq)
 		if (*ttyreq > ttys->max)
 			goto out;
 
-		if (ttys->tty[*ttyreq - 1].busy)
+		if (ttys->tty[*ttyreq - 1].busy >= 0)
 			goto out;
 
 		/* The requested tty is available. */
@@ -602,7 +602,7 @@ int lxc_terminal_allocate(struct lxc_conf *conf, int sockfd, int *ttyreq)
 	}
 
 	/* Search for next available tty, fixup index tty1 => [0]. */
-	for (ttynum = 1; ttynum <= ttys->max && ttys->tty[ttynum - 1].busy; ttynum++) {
+	for (ttynum = 1; ttynum <= ttys->max && ttys->tty[ttynum - 1].busy >= 0; ttynum++) {
 		;
 	}
 
@@ -628,7 +628,7 @@ void lxc_terminal_free(struct lxc_conf *conf, int fd)
 
 	for (i = 0; i < ttys->max; i++)
 		if (ttys->tty[i].busy == fd)
-			ttys->tty[i].busy = 0;
+			ttys->tty[i].busy = -1;
 
 	if (terminal->proxy.busy != fd)
 		return;