From: Greg KH <greg@press.(none)>
Date: Thu, 19 May 2005 06:32:28 +0000 (-0700)
Subject: Fix libsysfs issue with relying on the detach_state file to be
X-Git-Tag: 058~5
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=commitdiff_plain;h=b479b4887f5a0eb69b801645ab1b14636c4b06a2

Fix libsysfs issue with relying on the detach_state file to be
present in order to traverse the tree properly.

Based on a patch from Daniel Stekloff <dsteklof@us.ibm.com>

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/libsysfs/sysfs_device.c b/libsysfs/sysfs_device.c
index d1c5b321f..1c59403ed 100644
--- a/libsysfs/sysfs_device.c
+++ b/libsysfs/sysfs_device.c
@@ -383,7 +383,7 @@ struct sysfs_device *sysfs_open_device(const char *bus,	const char *bus_id)
  */
 struct sysfs_device *sysfs_get_device_parent(struct sysfs_device *dev)
 {
-	char ppath[SYSFS_PATH_MAX], *tmp;
+	char ppath[SYSFS_PATH_MAX], dpath[SYSFS_PATH_MAX], *tmp;
 
 	if (!dev) {
 		errno = EINVAL;
@@ -394,6 +394,7 @@ struct sysfs_device *sysfs_get_device_parent(struct sysfs_device *dev)
 		return (dev->parent);
 
 	memset(ppath, 0, SYSFS_PATH_MAX);
+	memset(dpath, 0, SYSFS_PATH_MAX);
 	safestrcpy(ppath, dev->path);
 	tmp = strrchr(ppath, '/');
 	if (!tmp) {
@@ -410,16 +411,14 @@ struct sysfs_device *sysfs_get_device_parent(struct sysfs_device *dev)
 	}
 	*tmp = '\0';
 
-	/*
-	 * All "devices" have the "detach_state" attribute - validate here
-	 */
-	safestrcat(ppath, "/detach_state");
-	if (sysfs_path_is_file(ppath)) {
+	/* Make sure we're not at the top of the device tree */
+	sysfs_get_mnt_path(dpath, SYSFS_PATH_MAX);
+	safestrcat(dpath, "/" SYSFS_DEVICES_NAME);
+	if (strcmp(dpath, ppath) == 0) {
 		dprintf("Device at %s does not have a parent\n", dev->path);
 		return NULL;
 	}
-	tmp = strrchr(ppath, '/');
-	*tmp = '\0';
+
 	dev->parent = sysfs_open_device_path(ppath);
 	if (!dev->parent) {
 		dprintf("Error opening device %s's parent at %s\n",