From 2f86ca135069e457bb16ab9e062a10e0775717a6 Mon Sep 17 00:00:00 2001
From: Denys Vlasenko <vda.linux@googlemail.com>
Date: Mon, 22 Jun 2009 01:31:12 +0200
Subject: [PATCH] mdev: fix the case when move rule deletes node with name ==
 device_name

Signed-off-by: Jean Wolter <jw5@os.inf.tu-dresden.de>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
---
 testsuite/mdev.tests | 26 ++++++++++++++++++++++++++
 util-linux/mdev.c    | 36 +++++++++++++++++-------------------
 2 files changed, 43 insertions(+), 19 deletions(-)

diff --git a/testsuite/mdev.tests b/testsuite/mdev.tests
index a1750076e..912785ece 100755
--- a/testsuite/mdev.tests
+++ b/testsuite/mdev.tests
@@ -162,6 +162,32 @@ brw-r--r-- 1 0 1 8,0 sda
 " \
 	"" ""
 
+# continuing to use directory structure from prev test
+rm -rf mdev.testdir/dev/*
+mkdir -p mdev.testdir/sys/class/tty/capi
+echo "191:0" >mdev.testdir/sys/class/tty/capi/dev
+mkdir -p mdev.testdir/sys/class/tty/capi1
+echo "191:1" >mdev.testdir/sys/class/tty/capi1/dev
+mkdir -p mdev.testdir/sys/class/tty/capi20
+echo "191:20" >mdev.testdir/sys/class/tty/capi20/dev
+echo "capi            0:0 0660 =capi20"      >mdev.testdir/etc/mdev.conf
+echo "capi([0-9])     0:0 0660 =capi20.0%1" >>mdev.testdir/etc/mdev.conf
+echo "capi([0-9]*)    0:0 0660 =capi20.%1"  >>mdev.testdir/etc/mdev.conf
+# mdev invocation with DEVPATH=/class/tty/capi20 was deleting /dev/capi20
+testing "move rule does not delete node with name == device_name" \
+	"\
+	env - PATH=$PATH ACTION=add DEVPATH=/class/tty/capi chroot mdev.testdir /mdev 2>&1;
+	env - PATH=$PATH ACTION=add DEVPATH=/class/tty/capi1 chroot mdev.testdir /mdev 2>&1;
+	env - PATH=$PATH ACTION=add DEVPATH=/class/tty/capi20 chroot mdev.testdir /mdev 2>&1;
+	ls -lnR mdev.testdir/dev | $FILTER_LS" \
+"\
+mdev.testdir/dev:
+crw-rw---- 1 0 0 191,0 capi20
+crw-rw---- 1 0 0 191,1 capi20.01
+crw-rw---- 1 0 0 191,20 capi20.20
+" \
+	"" ""
+
 # clean up
 rm -rf mdev.testdir
 
diff --git a/util-linux/mdev.c b/util-linux/mdev.c
index 7508930f7..c68c0a5e7 100644
--- a/util-linux/mdev.c
+++ b/util-linux/mdev.c
@@ -319,22 +319,20 @@ static void make_device(char *path, int delete)
 		/* "Execute" the line we found */
 
 		if (!delete && major >= 0) {
-			if (ENABLE_FEATURE_MDEV_RENAME)
-				unlink(device_name);
-			if (mknod(device_name, mode | type, makedev(major, minor)) && errno != EEXIST)
-				bb_perror_msg_and_die("mknod %s", device_name);
+			char *node_name = (char *)device_name;
+			if (ENABLE_FEATURE_MDEV_RENAME && alias)
+				alias = node_name = build_alias(alias, device_name);
+			if (mknod(node_name, mode | type, makedev(major, minor)) && errno != EEXIST)
+				bb_perror_msg_and_die("mknod %s", node_name);
 			if (major == root_major && minor == root_minor)
-				symlink(device_name, "root");
+				symlink(node_name, "root");
 			if (ENABLE_FEATURE_MDEV_CONF) {
-				chmod(device_name, mode);
-				chown(device_name, ugid.uid, ugid.gid);
+				chmod(node_name, mode);
+				chown(node_name, ugid.uid, ugid.gid);
 			}
 			if (ENABLE_FEATURE_MDEV_RENAME && alias) {
-				alias = build_alias(alias, device_name);
-				/* move the device, and optionally
-				 * make a symlink to moved device node */
-				if (rename(device_name, alias) == 0 && aliaslink == '>')
-					symlink(alias, device_name);
+				if (aliaslink == '>')
+					symlink(node_name, device_name);
 				free(alias);
 			}
 		}
@@ -355,15 +353,15 @@ static void make_device(char *path, int delete)
 		}
 
 		if (delete) {
-			unlink(device_name);
-			/* At creation time, device might have been moved
-			 * and a symlink might have been created. Undo that. */
-
+			char *node_name = (char *)device_name;
 			if (ENABLE_FEATURE_MDEV_RENAME && alias) {
-				alias = build_alias(alias, device_name);
-				unlink(alias);
-				free(alias);
+				alias = node_name = build_alias(alias, device_name);
+				if (aliaslink == '>')
+					unlink(device_name);
 			}
+			unlink(node_name);
+			if (ENABLE_FEATURE_MDEV_RENAME)
+				free(alias);
 		}
 
 		/* We found matching line.