[PATCH] big libsysfs diet (pre 2.0 version)

1 files changed, 210 insertions, 790 deletions

diff --git a/libsysfs/sysfs_dir.c b/libsysfs/sysfs_dir.c
index 52769916cc..c86617934b 100644
--- a/libsysfs/sysfs_dir.c
+++ b/libsysfs/sysfs_dir.c
@@ -3,7 +3,7 @@
  *
  * Directory utility functions for libsysfs
  *
- * Copyright (C) IBM Corp. 2003
+ * Copyright (C) IBM Corp. 2003-2005
  *
  *  This library is free software; you can redistribute it and/or
  *  modify it under the terms of the GNU Lesser General Public
@@ -23,39 +23,38 @@
 #include "libsysfs.h"
 #include "sysfs.h"
 
-/**
- * sysfs_del_attribute: routine for dlist integration
- */
-static void sysfs_del_attribute(void *attr)
+static int sort_char(void *new, void *old)
 {
-        sysfs_close_attribute((struct sysfs_attribute *)attr);
+	return ((strncmp((char *)new, (char *)old, 
+			strlen((char *)new))) < 0 ? 1 : 0);
 }
 
 /**
- * sysfs_del_link: routine for dlist integration
+ * sysfs_del_name: free function for sysfs_open_subsystem_list
+ * @name: memory area to be freed
  */
-static void sysfs_del_link(void *ln)
+static void sysfs_del_name(void *name)
 {
-        sysfs_close_link((struct sysfs_link *)ln);
+	free(name);
 }
 
 /**
- * sysfs_del_dir: routine for dlist integration
+ * sysfs_del_attribute: routine for dlist integration
  */
-static void sysfs_del_directory(void *dir)
+static void sysfs_del_attribute(void *attr)
 {
-        sysfs_close_directory((struct sysfs_directory *)dir);
+	sysfs_close_attribute((struct sysfs_attribute *)attr);
 }
 
 /**
- * dir_attribute_name_equal: compares dir attributes by name
+ * attr_name_equal: compares attributes by name
  * @a: attribute name for comparison
  * @b: sysfs_attribute to be compared.
  * returns 1 if a==b->name or 0 if not equal
  */
-static int dir_attribute_name_equal(void *a, void *b)
+static int attr_name_equal(void *a, void *b)
 {
-	if (a == NULL || b == NULL)
+	if (!a || !b)
 		return 0;
 
 	if (strcmp(((char *)a), ((struct sysfs_attribute *)b)->name) == 0)
@@ -65,47 +64,13 @@ static int dir_attribute_name_equal(void *a, void *b)
 }
 
 /**
- * dir_link_name_equal: compares dir links by name
- * @a: link name for comparison
- * @b: sysfs_link to be compared.
- * returns 1 if a==b->name or 0 if not equal
- */
-static int dir_link_name_equal(void *a, void *b)
-{
-	if (a == NULL || b == NULL)
-		return 0;
-
-	if (strcmp(((char *)a), ((struct sysfs_link *)b)->name) == 0)
-		return 1;
-
-	return 0;
-}
-
-/**
- * dir_subdir_name_equal: compares subdirs by name
- * @a: name of subdirectory to compare
- * @b: sysfs_directory subdirectory to be compared
- * returns 1 if a==b->name or 0 if not equal
- */
-static int dir_subdir_name_equal(void *a, void *b)
-{
-	if (a == NULL || b == NULL)
-		return 0;
-
-	if (strcmp(((char *)a), ((struct sysfs_directory *)b)->name) == 0)
-		return 1;
-
-	return 0;
-}
-
-/**
  * sysfs_close_attribute: closes and cleans up attribute
  * @sysattr: attribute to close.
  */
 void sysfs_close_attribute(struct sysfs_attribute *sysattr)
 {
-	if (sysattr != NULL) {
-		if (sysattr->value != NULL)
+	if (sysattr) {
+		if (sysattr->value)
 			free(sysattr->value);
 		free(sysattr);
 	}
@@ -130,13 +95,13 @@ struct sysfs_attribute *sysfs_open_attribute(const char *path)
 {
 	struct sysfs_attribute *sysattr = NULL;
 	struct stat fileinfo;
-	
-	if (path == NULL) {
+
+	if (!path) {
 		errno = EINVAL;
 		return NULL;
 	}
 	sysattr = alloc_attribute();
-	if (sysattr == NULL) {
+	if (!sysattr) {
 		dprintf("Error allocating attribute at %s\n", path);
 		return NULL;
 	}
@@ -163,94 +128,6 @@ struct sysfs_attribute *sysfs_open_attribute(const char *path)
 }
 
 /**
- * sysfs_write_attribute: write value to the attribute
- * @sysattr: attribute to write
- * @new_value: value to write
- * @len: length of "new_value"
- * returns 0 with success and -1 with error.
- */
-int sysfs_write_attribute(struct sysfs_attribute *sysattr,
-		const char *new_value, size_t len)
-{
-	int fd;
-	int length;
-	
-	if (sysattr == NULL || new_value == NULL || len == 0) {
-		errno = EINVAL;
-		return -1;
-	}
-	
-	if (!(sysattr->method & SYSFS_METHOD_STORE)) {
-		dprintf ("Store method not supported for attribute %s\n",
-			sysattr->path);
-		errno = EACCES;
-		return -1;
-	}
-	if (sysattr->method & SYSFS_METHOD_SHOW) {
-		/*
-		 * read attribute again to see if we can get an updated value 
-		 */
-		if ((sysfs_read_attribute(sysattr)) != 0) {
-			dprintf("Error reading attribute\n");
-			return -1;
-		}
-		if ((strncmp(sysattr->value, new_value, sysattr->len)) == 0) {
-			dprintf("Attr %s already has the requested value %s\n",
-					sysattr->name, new_value);
-			return 0;	
-		}
-	}
-	/* 
-	 * open O_WRONLY since some attributes have no "read" but only
-	 * "write" permission 
-	 */ 
-	if ((fd = open(sysattr->path, O_WRONLY)) < 0) {
-		dprintf("Error reading attribute %s\n", sysattr->path);
-		return -1;
-	}
-
-	length = write(fd, new_value, len);
-	if (length < 0) {
-		dprintf("Error writing to the attribute %s - invalid value?\n",
-			sysattr->name);
-		close(fd);
-		return -1;
-	} else if ((unsigned int)length != len) {
-		dprintf("Could not write %d bytes to attribute %s\n", 
-					len, sysattr->name);
-		/* 
-		 * since we could not write user supplied number of bytes,
-		 * restore the old value if one available
-		 */
-		if (sysattr->method & SYSFS_METHOD_SHOW) {
-			length = write(fd, sysattr->value, sysattr->len);
-			close(fd);
-			return -1;
-		}
-	}
-	
-	/*
-	 * Validate length that has been copied. Alloc appropriate area
-	 * in sysfs_attribute. Verify first if the attribute supports reading
-	 * (show method). If it does not, do not bother
-	 */ 
-	if (sysattr->method & SYSFS_METHOD_SHOW) {
-		if (length != sysattr->len) {
-			sysattr->value = (char *)realloc
-				(sysattr->value, length);
-			sysattr->len = length;
-			safestrcpymax(sysattr->value, new_value, length);
-		} else {
-			/*"length" of the new value is same as old one */ 
-			safestrcpymax(sysattr->value, new_value, length);
-		}
-	}
-			
-	close(fd);	
-	return 0;
-}
-
-/**
  * sysfs_read_attribute: reads value from attribute
  * @sysattr: attribute to read
  * returns 0 with success and -1 with error.
@@ -263,7 +140,7 @@ int sysfs_read_attribute(struct sysfs_attribute *sysattr)
 	long pgsize = 0;
 	int fd;
 
-	if (sysattr == NULL) {
+	if (!sysattr) {
 		errno = EINVAL;
 		return -1;
 	}
@@ -275,7 +152,7 @@ int sysfs_read_attribute(struct sysfs_attribute *sysattr)
 	}
 	pgsize = sysconf(_SC_PAGESIZE);
 	fbuf = (char *)calloc(1, pgsize+1);
-	if (fbuf == NULL) {
+	if (!fbuf) {
 		dprintf("calloc failed\n");
 		return -1;
 	}
@@ -303,7 +180,7 @@ int sysfs_read_attribute(struct sysfs_attribute *sysattr)
 	sysattr->len = length;
 	close(fd);
 	vbuf = (char *)realloc(fbuf, length+1);
-	if (vbuf == NULL) {
+	if (!vbuf) {
 		dprintf("realloc failed\n");
 		free(fbuf);
 		return -1;
@@ -314,758 +191,301 @@ int sysfs_read_attribute(struct sysfs_attribute *sysattr)
 }
 
 /**
- * sysfs_read_attribute_value: given path to attribute, return its value.
- *	values can be up to a pagesize, if buffer is smaller the value will 
- *	be truncated. 
- * @attrpath: sysfs path to attribute
- * @value: buffer to put value
- * @vsize: size of value buffer
+ * sysfs_write_attribute: write value to the attribute
+ * @sysattr: attribute to write
+ * @new_value: value to write
+ * @len: length of "new_value"
  * returns 0 with success and -1 with error.
  */
-int sysfs_read_attribute_value(const char *attrpath, 
-					char *value, size_t vsize)
+int sysfs_write_attribute(struct sysfs_attribute *sysattr,
+		const char *new_value, size_t len)
 {
-	struct sysfs_attribute *attr = NULL;
-	size_t length = 0;
+	int fd;
+	int length;
 
-	if (attrpath == NULL || value == NULL || vsize == 0) {
+	if (!sysattr || !new_value || len == 0) {
 		errno = EINVAL;
 		return -1;
 	}
 
-	attr = sysfs_open_attribute(attrpath);
-	if (attr == NULL) {
-		dprintf("Invalid attribute path %s\n", attrpath);
-		errno = EINVAL;
-		return -1;
-	}
-	if((sysfs_read_attribute(attr)) != 0 || attr->value == NULL) {
-		dprintf("Error reading from attribute %s\n", attrpath);
-		sysfs_close_attribute(attr);
+	if (!(sysattr->method & SYSFS_METHOD_STORE)) {
+		dprintf ("Store method not supported for attribute %s\n",
+			sysattr->path);
+		errno = EACCES;
 		return -1;
 	}
-	length = strlen(attr->value);
-	if (length > vsize) 
-		dprintf("Value length %d is larger than supplied buffer %d\n",
-			length, vsize);
-	safestrcpymax(value, attr->value, vsize);
-	sysfs_close_attribute(attr);
-
-	return 0;
-}
-
-/**
- * sysfs_get_value_from_attrbutes: given a linked list of attributes and an 
- * 	attribute name, return its value
- * @attr: attribute to search
- * @name: name to look for
- * returns char * value - could be NULL
- */
-char *sysfs_get_value_from_attributes(struct dlist *attr, const char *name)
-{	
-	struct sysfs_attribute *cur = NULL;
-	
-	if (attr == NULL || name == NULL) {
-		errno = EINVAL;
-		return NULL;
-	}
-	dlist_for_each_data(attr, cur, struct sysfs_attribute) {
-		if (strcmp(cur->name, name) == 0)
-			return cur->value;
+	if (sysattr->method & SYSFS_METHOD_SHOW) {
+		/*
+		 * read attribute again to see if we can get an updated value 
+		 */
+		if ((sysfs_read_attribute(sysattr))) {
+			dprintf("Error reading attribute\n");
+			return -1;
+		}
+		if ((strncmp(sysattr->value, new_value, sysattr->len)) == 0) {
+			dprintf("Attr %s already has the requested value %s\n",
+					sysattr->name, new_value);
+			return 0;	
+		}
 	}
-	return NULL;
-}
-
-/**
- * sysfs_close_link: closes and cleans up link.
- * @ln: link to close.
- */
-void sysfs_close_link(struct sysfs_link *ln)
-{
-	if (ln != NULL) 
-		free(ln);
-}
-
-/**
- * sysfs_close_directory: closes directory, cleans up attributes and links
- * @sysdir: sysfs_directory to close
- */
-void sysfs_close_directory(struct sysfs_directory *sysdir)
-{
-	if (sysdir != NULL) {
-		if (sysdir->subdirs != NULL) 
-			dlist_destroy(sysdir->subdirs);
-		if (sysdir->links != NULL)
-			dlist_destroy(sysdir->links);
-		if (sysdir->attributes != NULL) 
-			dlist_destroy(sysdir->attributes);
-		free(sysdir);
-		sysdir = NULL;
+	/*
+	 * open O_WRONLY since some attributes have no "read" but only
+	 * "write" permission 
+	 */
+	if ((fd = open(sysattr->path, O_WRONLY)) < 0) {
+		dprintf("Error reading attribute %s\n", sysattr->path);
+		return -1;
 	}
-}
-
-/**
- * alloc_directory: allocates and initializes directory structure
- * returns struct sysfs_directory with success or NULL with error.
- */
-static struct sysfs_directory *alloc_directory(void)
-{
-	return (struct sysfs_directory *)
-			calloc(1, sizeof(struct sysfs_directory));
-}
-
-/**
- * alloc_link: allocates and initializes link structure
- * returns struct sysfs_link with success or NULL with error.
- */
-static struct sysfs_link *alloc_link(void)
-{
-	return (struct sysfs_link *)calloc(1, sizeof(struct sysfs_link));
-}
-
-/**
- * sysfs_read_all_subdirs: calls sysfs_read_directory for all subdirs
- * @sysdir: directory whose subdirs need reading.
- * returns 0 with success and -1 with error.
- */
-int sysfs_read_all_subdirs(struct sysfs_directory *sysdir)
-{
-	struct sysfs_directory *cursub = NULL;
-	int retval = 0;
 
-	if (sysdir == NULL) {
-		errno = EINVAL;
+	length = write(fd, new_value, len);
+	if (length < 0) {
+		dprintf("Error writing to the attribute %s - invalid value?\n",
+			sysattr->name);
+		close(fd);
 		return -1;
-	}
-	if (sysdir->subdirs == NULL) 
-		if ((sysfs_read_dir_subdirs(sysdir)) != 0) 
-			return 0;
-	if (sysdir->subdirs != NULL) {
-		dlist_for_each_data(sysdir->subdirs, cursub, 
-						struct sysfs_directory) {
-			if ((sysfs_read_dir_subdirs(cursub)) != 0) {
-				dprintf ("Error reading subdirectory %s\n",
-						cursub->name);
-				retval = -1;
-			}
+	} else if ((unsigned int)length != len) {
+		dprintf("Could not write %d bytes to attribute %s\n", 
+					len, sysattr->name);
+		/* 
+		 * since we could not write user supplied number of bytes,
+		 * restore the old value if one available
+		 */
+		if (sysattr->method & SYSFS_METHOD_SHOW) {
+			length = write(fd, sysattr->value, sysattr->len);
+			close(fd);
+			return -1;
 		}
 	}
-	if (!retval)
-		errno = 0;
-	return retval;
-}
 
-/**
- * sysfs_open_directory: opens a sysfs directory, creates dir struct, and
- *		returns.
- * @path: path of directory to open.
- * returns: struct sysfs_directory * with success and NULL on error.
- */
-struct sysfs_directory *sysfs_open_directory(const char *path)
-{
-	struct sysfs_directory *sdir = NULL;
-
-	if (path == NULL) {
-		errno = EINVAL;
-		return NULL;
-	}
-
-	if (sysfs_path_is_dir(path) != 0) {
-		dprintf("Invalid path to directory %s\n", path);
-		errno = EINVAL;
-		return NULL;
-	}
-
-	sdir = alloc_directory();
-	if (sdir == NULL) {
-		dprintf("Error allocating directory %s\n", path);
-		return NULL;
-	}
-	if (sysfs_get_name_from_path(path, sdir->name, SYSFS_NAME_LEN) != 0) {
-		dprintf("Error getting directory name from path: %s\n", path);
-		sysfs_close_directory(sdir);
-		return NULL;
-	}
-	safestrcpy(sdir->path, path);
-
-	return sdir;
-}
-
-/**
- * sysfs_open_link: opens a sysfs link, creates struct, and returns
- * @path: path of link to open.
- * returns: struct sysfs_link * with success and NULL on error.
- */
-struct sysfs_link *sysfs_open_link(const char *linkpath)
-{
-	struct sysfs_link *ln = NULL;
-
-	if (linkpath == NULL || strlen(linkpath) > SYSFS_PATH_MAX) {
-		errno = EINVAL;
-		return NULL;
-	}
-
-	ln = alloc_link();
-	if (ln == NULL) {
-		dprintf("Error allocating link %s\n", linkpath);
-		return NULL;
-	}
-	safestrcpy(ln->path, linkpath);
-	if ((sysfs_get_name_from_path(linkpath, ln->name, SYSFS_NAME_LEN)) != 0
-	    || (sysfs_get_link(linkpath, ln->target, SYSFS_PATH_MAX)) != 0) {
-		sysfs_close_link(ln);
-		errno = EINVAL;
-		dprintf("Invalid link path %s\n", linkpath);
-		return NULL;
+	/*
+	 * Validate length that has been copied. Alloc appropriate area
+	 * in sysfs_attribute. Verify first if the attribute supports reading
+	 * (show method). If it does not, do not bother
+	 */ 
+	if (sysattr->method & SYSFS_METHOD_SHOW) {
+		if (length != sysattr->len) {
+			sysattr->value = (char *)realloc
+				(sysattr->value, length);
+			sysattr->len = length;
+			safestrcpymax(sysattr->value, new_value, length);
+		} else {
+			/*"length" of the new value is same as old one */ 
+			safestrcpymax(sysattr->value, new_value, length);
+		}
 	}
-
-	return ln;
+			
+	close(fd);	
+	return 0;
 }
 
 /**
  * add_attribute: open and add attribute at path to given directory
- * @sysdir: directory to add attribute to
+ * @dev: device whose attribute is to be added
  * @path: path to attribute
- * returns 0 with success and -1 with error.
+ * returns pointer to attr added with success and NULL with error.
  */
-static int add_attribute(struct sysfs_directory *sysdir, const char *path)
+static struct sysfs_attribute *add_attribute(void *dev, const char *path)
 {
-	struct sysfs_attribute *attr = NULL;
+	struct sysfs_attribute *attr;
 
 	attr = sysfs_open_attribute(path);
-	if (attr == NULL) {
+	if (!attr) {
 		dprintf("Error opening attribute %s\n",	path);
-		return -1;
+		return NULL;
 	}
 	if (attr->method & SYSFS_METHOD_SHOW) {
-		if ((sysfs_read_attribute(attr)) != 0) {
+		if (sysfs_read_attribute(attr)) {
 			dprintf("Error reading attribute %s\n",	path);
 			sysfs_close_attribute(attr);
-			return 0;
+			return NULL;
 		}
 	}
-			                        
-	if (sysdir->attributes == NULL) {
-		sysdir->attributes = dlist_new_with_delete
-			(sizeof(struct sysfs_attribute), sysfs_del_attribute);
-	}
-	dlist_unshift_sorted(sysdir->attributes, attr, sort_list);
-
-	return 0;
-}
-
-/**
- * add_subdirectory: open and add subdirectory at path to given directory
- * @sysdir: directory to add subdir to
- * @path: path to subdirectory
- * returns 0 with success and -1 with error.
- */
-static int add_subdirectory(struct sysfs_directory *sysdir, const char *path)
-{
-	struct sysfs_directory *subdir = NULL;
 
-	subdir = sysfs_open_directory(path);
-	if (subdir == NULL) {
-		dprintf("Error opening directory %s\n", path);
-		return -1;
+	if (!((struct sysfs_device *)dev)->attrlist) {
+		((struct sysfs_device *)dev)->attrlist = dlist_new_with_delete
+			(sizeof(struct sysfs_attribute), sysfs_del_attribute);
 	}
-	if (sysdir->subdirs == NULL)
-		sysdir->subdirs = dlist_new_with_delete
-			(sizeof(struct sysfs_directory), sysfs_del_directory);
-	dlist_unshift_sorted(sysdir->subdirs, subdir, sort_list);
-	return 0;
-}
+	dlist_unshift_sorted(((struct sysfs_device *)dev)->attrlist, 
+			attr, sort_list);
 
-/**
- * add_link: open and add link at path to given directory
- * @sysdir: directory to add link to
- * @path: path to link
- * returns 0 with success and -1 with error.
- */
-static int add_link(struct sysfs_directory *sysdir, const char *path)
-{
-	struct sysfs_link *ln = NULL;
-
-	ln = sysfs_open_link(path);
-	if (ln == NULL) {
-		dprintf("Error opening link %s\n", path);
-		return -1;
-	}
-	if (sysdir->links == NULL)
-		sysdir->links = dlist_new_with_delete
-				(sizeof(struct sysfs_link), sysfs_del_link);
-	dlist_unshift_sorted(sysdir->links, ln, sort_list);
-	return 0;
+	return attr;
 }
 
-/**
- * sysfs_read_dir_attributes: grabs attributes for the given directory
- * @sysdir: sysfs directory to open
- * returns 0 with success and -1 with error.
+/*
+ * get_attribute - given a sysfs_* struct and a name, return the 
+ * sysfs_attribute corresponding to "name"
+ * returns sysfs_attribute on success and NULL on error
  */
-int sysfs_read_dir_attributes(struct sysfs_directory *sysdir)
+struct sysfs_attribute *get_attribute(void *dev, const char *name)
 {
-	DIR *dir = NULL;
-	struct dirent *dirent = NULL;
-	char file_path[SYSFS_PATH_MAX];
-	int retval = 0;
+	struct sysfs_attribute *cur = NULL;
+	char path[SYSFS_PATH_MAX];
 
-	if (sysdir == NULL) {
+	if (!dev || !name) {
 		errno = EINVAL;
-		return -1;
-	}
-	dir = opendir(sysdir->path);
-	if (dir == NULL) {
-		dprintf("Error opening directory %s\n", sysdir->path);
-		return -1;
+		return NULL;
 	}
-	while(((dirent = readdir(dir)) != NULL) && retval == 0) {
-		if (0 == strcmp(dirent->d_name, "."))
-			 continue;
-		if (0 == strcmp(dirent->d_name, ".."))
-			continue;
-		memset(file_path, 0, SYSFS_PATH_MAX);
-		safestrcpy(file_path, sysdir->path);
-		safestrcat(file_path, "/");
-		safestrcat(file_path, dirent->d_name);
-		if ((sysfs_path_is_file(file_path)) == 0)
-			retval = add_attribute(sysdir, file_path);
+
+	if (((struct sysfs_device *)dev)->attrlist) {
+		/* check if attr is already in the list */
+		cur = (struct sysfs_attribute *)dlist_find_custom
+			((((struct sysfs_device *)dev)->attrlist), 
+			 	(void *)name, attr_name_equal);
+		if (cur)
+			return cur;
 	}
-	closedir(dir);
-	if (!retval)
-		errno = 0;
-	return(retval);
+	safestrcpymax(path, ((struct sysfs_device *)dev)->path, 
+			SYSFS_PATH_MAX);
+	safestrcatmax(path, "/", SYSFS_PATH_MAX);
+	safestrcatmax(path, name, SYSFS_PATH_MAX);
+	if (!(sysfs_path_is_file(path)))
+		cur = add_attribute((void *)dev, path);
+	return cur;
 }
 
 /**
- * sysfs_read_dir_links: grabs links in a specific directory
- * @sysdir: sysfs directory to read links
- * returns 0 with success and -1 with error.
+ * read_dir_links: grabs links in a specific directory
+ * @sysdir: sysfs directory to read
+ * returns list of link names with success and NULL with error.
  */
-int sysfs_read_dir_links(struct sysfs_directory *sysdir)
+struct dlist *read_dir_links(const char *path)
 {
 	DIR *dir = NULL;
 	struct dirent *dirent = NULL;
-	char file_path[SYSFS_PATH_MAX];
-	int retval = 0;
+	char file_path[SYSFS_PATH_MAX], *linkname;
+	struct dlist *linklist = NULL;
 
-	if (sysdir == NULL) {
+	if (!path) {
 		errno = EINVAL;
-		return -1;
+		return NULL;
 	}
-	dir = opendir(sysdir->path);
-	if (dir == NULL) {
-		dprintf("Error opening directory %s\n", sysdir->path);
-		return -1;
+	dir = opendir(path);
+	if (!dir) {
+		dprintf("Error opening directory %s\n", path);
+		return NULL;
 	}
-	while(((dirent = readdir(dir)) != NULL) && retval == 0) {
+	while ((dirent = readdir(dir)) != NULL) {
 		if (0 == strcmp(dirent->d_name, "."))
 			 continue;
 		if (0 == strcmp(dirent->d_name, ".."))
 			continue;
 		memset(file_path, 0, SYSFS_PATH_MAX);
-		safestrcpy(file_path, sysdir->path);
+		safestrcpy(file_path, path);
 		safestrcat(file_path, "/");
 		safestrcat(file_path, dirent->d_name);
 		if ((sysfs_path_is_link(file_path)) == 0) {
-			retval = add_link(sysdir, file_path);
-			if (retval != 0)
-				break;
+			if (!linklist) {
+				linklist = dlist_new_with_delete
+					(SYSFS_NAME_LEN, sysfs_del_name);
+				if (!linklist) {
+					dprintf("Error creating list\n");
+					return NULL;
+				}
+			}
+			linkname = (char *)calloc(1, SYSFS_NAME_LEN);
+			safestrcpymax(linkname, dirent->d_name, SYSFS_NAME_LEN);
+			dlist_unshift_sorted(linklist, linkname, sort_char);
 		}
 	}
 	closedir(dir);
-	if (!retval)
-		errno = 0;
-	return(retval);
+	return linklist;
 }
 
 /**
- * sysfs_read_dir_subdirs: grabs subdirs in a specific directory
- * @sysdir: sysfs directory to read links
- * returns 0 with success and -1 with error.
+ * read_dir_subdirs: grabs subdirs in a specific directory
+ * @sysdir: sysfs directory to read
+ * returns list of directory names with success and NULL with error.
  */
-int sysfs_read_dir_subdirs(struct sysfs_directory *sysdir)
+struct dlist *read_dir_subdirs(const char *path)
 {
 	DIR *dir = NULL;
 	struct dirent *dirent = NULL;
-	char file_path[SYSFS_PATH_MAX];
-	int retval = 0;
+	char file_path[SYSFS_PATH_MAX], *dir_name;
+	struct dlist *dirlist = NULL;
 
-	if (sysdir == NULL) {
+	if (!path) {
 		errno = EINVAL;
-		return -1;
+		return NULL;
 	}
-	dir = opendir(sysdir->path);
-	if (dir == NULL) {
-		dprintf("Error opening directory %s\n", sysdir->path);
-		return -1;
+	dir = opendir(path);
+	if (!dir) {
+		dprintf("Error opening directory %s\n", path);
+		return NULL;
 	}
-	while(((dirent = readdir(dir)) != NULL) && retval == 0) {
+	while ((dirent = readdir(dir)) != NULL) {
 		if (0 == strcmp(dirent->d_name, "."))
 			 continue;
 		if (0 == strcmp(dirent->d_name, ".."))
 			continue;
 		memset(file_path, 0, SYSFS_PATH_MAX);
-		safestrcpy(file_path, sysdir->path);
+		safestrcpy(file_path, path);
 		safestrcat(file_path, "/");
 		safestrcat(file_path, dirent->d_name);
-		if ((sysfs_path_is_dir(file_path)) == 0)
-			retval = add_subdirectory(sysdir, file_path);
+		if ((sysfs_path_is_dir(file_path)) == 0) {
+			if (!dirlist) {
+				dirlist = dlist_new_with_delete
+					(SYSFS_NAME_LEN, sysfs_del_name);
+				if (!dirlist) {
+					dprintf("Error creating list\n");
+					return NULL;
+				}
+			}
+			dir_name = (char *)calloc(1, SYSFS_NAME_LEN);
+			safestrcpymax(dir_name, dirent->d_name, SYSFS_NAME_LEN);
+			dlist_unshift_sorted(dirlist, dir_name, sort_char);
+		}
 	}
 	closedir(dir);
-	if (!retval)
-		errno = 0;
-	return(retval);
+	return dirlist;
 }
 
 /**
- * sysfs_read_directory: grabs attributes, links, and subdirectories
- * @sysdir: sysfs directory to open
- * returns 0 with success and -1 with error.
+ * get_attributes_list: build a list of attributes for the given device
+ * @dev: devices whose attributes list is required
+ * returns dlist of attributes on success and NULL on failure
  */
-int sysfs_read_directory(struct sysfs_directory *sysdir)
+struct dlist *get_attributes_list(void *dev)
 {
 	DIR *dir = NULL;
 	struct dirent *dirent = NULL;
-	struct stat astats;
-	char file_path[SYSFS_PATH_MAX];
-	int retval = 0;
+	struct sysfs_attribute *attr = NULL;
+	char file_path[SYSFS_PATH_MAX], path[SYSFS_PATH_MAX];
 
-	if (sysdir == NULL) {
+	if (!dev) {
 		errno = EINVAL;
-		return -1;
+		return NULL;
 	}
-	dir = opendir(sysdir->path);
-	if (dir == NULL) {
-		dprintf("Error opening directory %s\n", sysdir->path);
-		return -1;
+	memset(path, 0, SYSFS_PATH_MAX);
+	safestrcpy(path, ((struct sysfs_device *)dev)->path);
+	dir = opendir(path);
+	if (!dir) {
+		dprintf("Error opening directory %s\n", path);
+		return NULL;
 	}
-	while(((dirent = readdir(dir)) != NULL) && retval == 0) {
+	while ((dirent = readdir(dir)) != NULL) {
 		if (0 == strcmp(dirent->d_name, "."))
 			 continue;
 		if (0 == strcmp(dirent->d_name, ".."))
 			continue;
 		memset(file_path, 0, SYSFS_PATH_MAX);
-		safestrcpy(file_path, sysdir->path);
+		safestrcpy(file_path, path);
 		safestrcat(file_path, "/");
 		safestrcat(file_path, dirent->d_name);
-		if ((lstat(file_path, &astats)) != 0) {
-			dprintf("stat failed\n");
-			continue;
-		}
-		if (S_ISDIR(astats.st_mode)) 
-			retval = add_subdirectory(sysdir, file_path);
-
-		else if (S_ISLNK(astats.st_mode))
-			retval = add_link(sysdir, file_path);
-
-		else if (S_ISREG(astats.st_mode))
-			retval = add_attribute(sysdir, file_path);
-	}
-	closedir(dir);
-	if (!retval)
-		errno = 0;
-	return(retval);
-}
-
-/**
- * sysfs_refresh_dir_attributes: Refresh attributes list
- * @sysdir: directory whose list of attributes to refresh
- * Returns 0 on success, 1 on failure
- */
-int sysfs_refresh_dir_attributes(struct sysfs_directory *sysdir)
-{
-	if (sysdir == NULL) {
-		errno = EINVAL;
-		return 1;
-	}
-	if ((sysfs_path_is_dir(sysdir->path)) != 0) {
-		dprintf("Invalid path to directory %s\n", sysdir->path);
-		errno = EINVAL;
-		return 1;
-	}
-	if (sysdir->attributes != NULL) {
-		dlist_destroy(sysdir->attributes);
-		sysdir->attributes = NULL;
-	}
-	if ((sysfs_read_dir_attributes(sysdir)) != 0) {
-		dprintf("Error refreshing attributes for directory %s\n", 
-							sysdir->path);
-		return 1;
-	}
-	errno = 0;
-	return 0;
-}
-
-/**
- * sysfs_refresh_dir_links: Refresh links list
- * @sysdir: directory whose list of links to refresh
- * Returns 0 on success, 1 on failure
- */
-int sysfs_refresh_dir_links(struct sysfs_directory *sysdir)
-{
-	if (sysdir == NULL) {
-		errno = EINVAL;
-		return 1;
-	}
-	if ((sysfs_path_is_dir(sysdir->path)) != 0) {
-		dprintf("Invalid path to directory %s\n", sysdir->path);
-		errno = EINVAL;
-		return 1;
-	}
-	if (sysdir->links != NULL) {
-		dlist_destroy(sysdir->links);
-		sysdir->links = NULL;
-	}
-	if ((sysfs_read_dir_links(sysdir)) != 0) {
-		dprintf("Error refreshing links for directory %s\n", 
-							sysdir->path);
-		return 1;
-	}
-	errno = 0;
-	return 0;
-}
-
-/**
- * sysfs_refresh_dir_subdirs: Refresh subdirs list
- * @sysdir: directory whose list of subdirs to refresh
- * Returns 0 on success, 1 on failure
- */
-int sysfs_refresh_dir_subdirs(struct sysfs_directory *sysdir)
-{
-	if (sysdir == NULL) {
-		errno = EINVAL;
-		return 1;
-	}
-	if ((sysfs_path_is_dir(sysdir->path)) != 0) {
-		dprintf("Invalid path to directory %s\n", sysdir->path);
-		errno = EINVAL;
-		return 1;
-	}
-	if (sysdir->subdirs != NULL) {
-		dlist_destroy(sysdir->subdirs);
-		sysdir->subdirs = NULL;
-	}
-	if ((sysfs_read_dir_subdirs(sysdir)) != 0) {
-		dprintf("Error refreshing subdirs for directory %s\n", 
-							sysdir->path);
-		return 1;
-	}
-	errno = 0;
-	return 0;
-}
-
-/**
- * sysfs_get_directory_attribute: retrieves attribute attrname from current
- *	directory only
- * @dir: directory to retrieve attribute from
- * @attrname: name of attribute to look for
- *
- * NOTE: Since we know the attribute to look for, this routine looks for the
- * 	attribute if it was created _after_ the attrlist was read initially.
- * 	
- * returns sysfs_attribute if found and NULL if not found
- */
-struct sysfs_attribute *sysfs_get_directory_attribute
-			(struct sysfs_directory *dir, char *attrname)
-{
-	struct sysfs_attribute *attr = NULL;
-	char new_path[SYSFS_PATH_MAX];
-	
-	if (dir == NULL || attrname == NULL) {
-		errno = EINVAL;
-		return NULL;
-	}
-
-	if (dir->attributes == NULL) 
-		if ((sysfs_read_dir_attributes(dir) != 0) 
-		    || (dir->attributes == NULL))
-			return NULL;
-
-	attr = (struct sysfs_attribute *)dlist_find_custom
-			(dir->attributes, attrname, dir_attribute_name_equal);
-	if (attr != NULL) {
-		if ((attr->method & SYSFS_METHOD_SHOW) &&
-			(sysfs_read_attribute(attr)) != 0) {
-			dprintf("Error reading attribute %s\n", attr->name);
-			return NULL;
-		}
-	} else {
-		memset(new_path, 0, SYSFS_PATH_MAX);
-		safestrcpy(new_path, dir->path);
-		safestrcat(new_path, "/");
-		safestrcat(new_path, attrname);
-		if ((sysfs_path_is_file(new_path)) == 0) {
-			if ((add_attribute(dir, new_path)) == 0) {
+		if ((sysfs_path_is_file(file_path)) == 0) {
+			if (((struct sysfs_device *)dev)->attrlist) {
+				/* check if attr is already in the list */
 				attr = (struct sysfs_attribute *)
-					dlist_find_custom(dir->attributes,
-					attrname, dir_attribute_name_equal);
-			}
-		}
-	}
-		
-	return attr;
-}
-
-/**
- * sysfs_get_directory_link: retrieves link from one directory list
- * @dir: directory to retrieve link from
- * @linkname: name of link to look for
- * returns reference to sysfs_link if found and NULL if not found
- */
-struct sysfs_link *sysfs_get_directory_link
-			(struct sysfs_directory *dir, char *linkname)
-{
-	if (dir == NULL || linkname == NULL) {
-		errno = EINVAL;
-		return NULL;
-	}
-	if (dir->links == NULL) {
-		if ((sysfs_read_dir_links(dir) != 0) || (dir->links == NULL))
-			return NULL;
-	} else {
-		if ((sysfs_refresh_dir_links(dir)) != 0) 
-			return NULL;
-	}
-
-	return (struct sysfs_link *)dlist_find_custom(dir->links,
-		linkname, dir_link_name_equal);
-}
-
-/**
- * sysfs_get_subdirectory: retrieves subdirectory by name.
- * @dir: directory to search for subdirectory.
- * @subname: subdirectory name to get.
- * returns reference to subdirectory or NULL if not found
- */
-struct sysfs_directory *sysfs_get_subdirectory(struct sysfs_directory *dir,
-						char *subname)
-{
-	struct sysfs_directory *sub = NULL, *cursub = NULL;
-
-	if (dir == NULL || subname == NULL) {
-		errno = EINVAL;
-		return NULL;
-	}
-
-	if (dir->subdirs == NULL)
-		if (sysfs_read_dir_subdirs(dir) != 0)
-			return NULL;
-
-	sub = (struct sysfs_directory *)dlist_find_custom(dir->subdirs,
-		subname, dir_subdir_name_equal);
-	if (sub != NULL) 
-		return sub;
-
-	if (dir->subdirs != NULL) {
-		dlist_for_each_data(dir->subdirs, cursub, 
-					struct sysfs_directory) {
-			if (cursub->subdirs == NULL) {
-				if (sysfs_read_dir_subdirs(cursub) != 0)
-					continue;
-				if (cursub->subdirs == NULL)
+				dlist_find_custom
+				((((struct sysfs_device *)dev)->attrlist), 
+			 	(void *)dirent->d_name, attr_name_equal);
+				if (attr) 
 					continue;
-			}
-			sub = sysfs_get_subdirectory(cursub, subname);
-			if (sub != NULL)
-				return sub;
-		}
-	}
-	return NULL;
-}
-
-/**
- * sysfs_get_subdirectory_link: looks through all subdirs for specific link.
- * @dir: directory and subdirectories to search for link.
- * @linkname: link name to get.
- * returns reference to link or NULL if not found
- */
-struct sysfs_link *sysfs_get_subdirectory_link(struct sysfs_directory *dir,
-						char *linkname)
-{
-	struct sysfs_directory *cursub = NULL;
-	struct sysfs_link *ln = NULL;
-
-	if (dir == NULL || linkname == NULL) {
-		errno = EINVAL;
-		return NULL;
-	}
-
-	ln = sysfs_get_directory_link(dir, linkname);
-	if (ln != NULL)
-		return ln;
-
-	if (dir->subdirs == NULL) 
-		if (sysfs_read_dir_subdirs(dir) != 0)
-			return NULL;
-
-	if (dir->subdirs != NULL) {
-		dlist_for_each_data(dir->subdirs, cursub, 
-						struct sysfs_directory) {
-			ln = sysfs_get_subdirectory_link(cursub, linkname);
-			if (ln != NULL)
-				return ln;
+				else 
+					add_attribute(dev, file_path);
+			} else 
+				attr = add_attribute(dev, file_path);
 		}
 	}
-	return NULL;
-}
-
-/**
- * sysfs_get_dir_attributes: returns dlist of directory attributes
- * @dir: directory to retrieve attributes from
- * returns dlist of attributes or NULL
- */
-struct dlist *sysfs_get_dir_attributes(struct sysfs_directory *dir)
-{
-	if (dir == NULL) {
-		errno = EINVAL;
-		return NULL;
-	}
-
-	if (dir->attributes == NULL) {
-		if (sysfs_read_dir_attributes(dir) != 0)
-			return NULL;
-	}
-
-	return (dir->attributes);
-}
-
-/**
- * sysfs_get_dir_links: returns dlist of directory links
- * @dir: directory to return links for
- * returns dlist of links or NULL
- */
-struct dlist *sysfs_get_dir_links(struct sysfs_directory *dir)
-{
-	if (dir == NULL) {
-		errno = EINVAL;
-		return NULL;
-	}
-
-	if (dir->links == NULL) {
-		if (sysfs_read_dir_links(dir) != 0)
-			return NULL;
-	}
-
-	return (dir->links);
-}
-
-/**
- * sysfs_get_dir_subdirs: returns dlist of directory subdirectories
- * @dir: directory to return subdirs for
- * returns dlist of subdirs or NULL
- */
-struct dlist *sysfs_get_dir_subdirs(struct sysfs_directory *dir)
-{
-	if (dir == NULL) {
-		errno = EINVAL;
-		return NULL;
-	}
-
-	if (dir->subdirs == NULL) {
-		if (sysfs_read_dir_subdirs(dir) != 0)
-			return NULL;
-	}
-
-	return (dir->subdirs);
+	closedir(dir);
+	return ((struct sysfs_device *)dev)->attrlist;
 }