Changes to dynamically read/refresh attributes

8 files changed, 88 insertions, 21 deletions

diff --git a/ChangeLog b/ChangeLog
index 7969c4f..5b2b373 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,4 +1,8 @@
 
+12/10/2003 - Ananth Mavinakayanahalli <ananth@in.ibm.com>
+		* Added more optimization changes
+		* Added code to add and refresh attributes dynamically
+
 12/08/2003 - Daniel Stekloff <dsteklof@us.ibm.com>
 		* Patched code for directory/attribute read optimization
 
diff --git a/include/libsysfs.h b/include/libsysfs.h
index 1a12d65..0939102 100644
--- a/include/libsysfs.h
+++ b/include/libsysfs.h
@@ -142,6 +142,8 @@ extern int sysfs_get_mnt_path(unsigned char *mnt_path, size_t len);
 extern int sysfs_get_name_from_path(const unsigned char *path, 
 					unsigned char *name, size_t len);
 extern int sysfs_path_is_dir(const unsigned char *path);
+extern int sysfs_path_is_link(const unsigned char *path);
+extern int sysfs_path_is_file(const unsigned char *path);
 extern int sysfs_get_link(const unsigned char *path, unsigned char *target, 
 								size_t len);
 extern struct dlist *sysfs_open_subsystem_list(unsigned char *name);
diff --git a/lib/sysfs_bus.c b/lib/sysfs_bus.c
index 615407e..0a7b171 100644
--- a/lib/sysfs_bus.c
+++ b/lib/sysfs_bus.c
@@ -335,6 +335,7 @@ struct dlist *sysfs_get_bus_attributes(struct sysfs_bus *bus)
 {
 	if (bus == NULL)
 		return NULL;
+
 	if (bus->directory == NULL) {
 		bus->directory = sysfs_open_directory(bus->path);
 		if (bus->directory == NULL)
@@ -344,6 +345,10 @@ struct dlist *sysfs_get_bus_attributes(struct sysfs_bus *bus)
 		if ((sysfs_read_dir_attributes(bus->directory)) != 0) 
 			return NULL;
 	} else {
+		if ((sysfs_path_is_dir(bus->path)) != 0) {
+			dprintf("Bus at %s no longer exists\n", bus->path);
+			return NULL;
+		}
 		if ((sysfs_refresh_attributes
 					(bus->directory->attributes)) != 0) {
 			dprintf("Error refreshing bus attributes\n");
diff --git a/lib/sysfs_class.c b/lib/sysfs_class.c
index 5d4da33..7d85f8f 100644
--- a/lib/sysfs_class.c
+++ b/lib/sysfs_class.c
@@ -538,6 +538,11 @@ struct dlist *sysfs_get_classdev_attributes(struct sysfs_class_device *cdev)
 			return NULL;
 		}
 	} else {
+		if ((sysfs_path_is_dir(cdev->path)) != 0) {
+			dprintf("Class device at %s no longer exists\n", 
+							cdev->path);
+			return NULL;
+		}
 		if ((sysfs_refresh_attributes
 					(cdev->directory->attributes)) != 0) {
 			dprintf("Error refreshing classdev attributes\n");
@@ -565,15 +570,13 @@ struct sysfs_attribute *sysfs_get_classdev_attr
 		return NULL;
 	}
 	
-	if (clsdev->directory == NULL) {
-		clsdev->directory = sysfs_open_directory(clsdev->path);
-		if (clsdev->directory == NULL) 
-			return NULL;
-	}
 	/* 
 	 * First, see if it's in the current directory. Then look at 
 	 * subdirs since class devices can have subdirs of attributes.
 	 */ 
+	attrlist = sysfs_get_classdev_attributes(clsdev);
+	if (attrlist == NULL)
+		return NULL;
 	cur = sysfs_get_directory_attribute(clsdev->directory,
 						(unsigned char *)name);
 	if (cur != NULL)
diff --git a/lib/sysfs_device.c b/lib/sysfs_device.c
index e5540dd..46e72ec 100644
--- a/lib/sysfs_device.c
+++ b/lib/sysfs_device.c
@@ -378,6 +378,10 @@ struct dlist *sysfs_get_device_attributes(struct sysfs_device *device)
 		if ((sysfs_read_dir_attributes(device->directory)) != 0)
 			return NULL;
 	} else {
+		if ((sysfs_path_is_dir(device->path)) != 0) {
+			dprintf("Device at %s no longer exists", device->path);
+			return NULL;
+		}
 		if ((sysfs_refresh_attributes
 				(device->directory->attributes)) != 0) {
 			dprintf("Error refreshing device attributes\n");
@@ -397,19 +401,15 @@ struct sysfs_attribute *sysfs_get_device_attr(struct sysfs_device *dev,
 						const unsigned char *name)
 {
 	struct sysfs_attribute *cur = NULL;
+	struct dlist *attrlist = NULL;
 
 	if (dev == NULL || name == NULL) {
 		errno = EINVAL;
 		return NULL;
 	}
 	
-	if (dev->directory == NULL) {
-		dev->directory = sysfs_open_directory(dev->path);
-		if (dev->directory == NULL)
-			return NULL;
-	}
-	dev->directory->attributes = sysfs_get_device_attributes(dev);
-	if (dev->directory->attributes == NULL)
+	attrlist = sysfs_get_device_attributes(dev);
+	if (attrlist == NULL)
 		return NULL;
 
 	cur = sysfs_get_directory_attribute(dev->directory, 
@@ -431,14 +431,14 @@ struct sysfs_attribute *sysfs_get_device_attr(struct sysfs_device *dev,
 static int get_device_absolute_path(const unsigned char *device,
 		const unsigned char *bus, unsigned char *path, size_t psize)
 {
-	unsigned char bus_path[SYSFS_NAME_LEN];
+	unsigned char bus_path[SYSFS_PATH_MAX];
 
 	if (device == NULL || path == NULL) {
 		errno = EINVAL;
 		return -1;
 	}
 
-	memset(bus_path, 0, SYSFS_NAME_LEN);
+	memset(bus_path, 0, SYSFS_PATH_MAX);
 	if (sysfs_get_mnt_path(bus_path, SYSFS_PATH_MAX) != 0) {
 		dprintf ("Sysfs not supported on this system\n");
 		return -1;
diff --git a/lib/sysfs_dir.c b/lib/sysfs_dir.c
index 7046d20..33fe4ec 100644
--- a/lib/sysfs_dir.c
+++ b/lib/sysfs_dir.c
@@ -524,10 +524,24 @@ int sysfs_refresh_attributes(struct dlist *attrlist)
 		if (attr->method & SYSFS_METHOD_SHOW) {
 			if ((sysfs_read_attribute(attr)) != 0) {
 				dprintf("Error reading attribute %s\n", path);
-				return 1;
+				if ((sysfs_path_is_file(attr->path)) != 0) {
+					dprintf("Attr %s no longer exists\n", 
+								attr->name);
+				}
+			}
+		} else {
+			if ((sysfs_path_is_file(attr->path)) != 0) {
+				dprintf("Attr %s no longer exists\n", 
+								attr->name);
 			}
 		}
 	}
+	if (attrlist->count == 0) {
+		dprintf("No attributes in the list, destroying list now\n");
+		dlist_destroy(attrlist);
+		attrlist = NULL;
+		return 1;
+	}
 	return 0;
 }
 
@@ -798,6 +812,7 @@ struct sysfs_attribute *sysfs_get_directory_attribute
 			(struct sysfs_directory *dir, unsigned char *attrname)
 {
 	struct sysfs_attribute *attr = NULL;
+	unsigned char new_path[SYSFS_PATH_MAX];
 	
 	if (dir == NULL || attrname == NULL) {
 		errno = EINVAL;
@@ -812,14 +827,24 @@ struct sysfs_attribute *sysfs_get_directory_attribute
 	attr = (struct sysfs_attribute *)dlist_find_custom
 			(dir->attributes, attrname, dir_attribute_name_equal);
 	if (attr != NULL) {
-		if ((sysfs_read_attribute(attr)) != 0) {
-			dprintf("Attribute at %s no longer exists?\n", 
-							attr->path);
-			return NULL;
-		} else
+		/*
+		 * don't read here since we would have read the attribute in 
+		 * in the routine that called this routine
+		 */ 
+		return attr;
+	} else {
+		memset(new_path, 0, SYSFS_PATH_MAX);
+		strcpy(new_path, dir->path);
+		strcat(new_path, "/");
+		strcat(new_path, attrname);
+		if ((sysfs_path_is_file(new_path)) == 0) {
+		 	if ((add_attribute(dir, new_path)) == 0) {
+				attr = (struct sysfs_attribute *)dlist_find_custom
+					(dir->attributes, attrname, dir_attribute_name_equal);
+			}
 			return attr;
+		}
 	}
-
 	return NULL;
 }
 
diff --git a/lib/sysfs_driver.c b/lib/sysfs_driver.c
index b243fc7..f2145e0 100644
--- a/lib/sysfs_driver.c
+++ b/lib/sysfs_driver.c
@@ -154,6 +154,11 @@ struct dlist *sysfs_get_driver_attributes(struct sysfs_driver *driver)
 			return NULL;
 		}
 	} else {
+		if ((sysfs_path_is_dir(driver->path)) != 0) {
+			dprintf("Driver at %s no longer exists\n", 
+							driver->path);
+			return NULL;
+		}
 		if ((sysfs_refresh_attributes
 				(driver->directory->attributes)) != 0) {
 			dprintf("Error refreshing driver attributes\n");
diff --git a/lib/sysfs_utils.c b/lib/sysfs_utils.c
index 7b71639..dd424f1 100644
--- a/lib/sysfs_utils.c
+++ b/lib/sysfs_utils.c
@@ -377,3 +377,26 @@ int sysfs_path_is_link(const unsigned char *path)
 		
 	return 1;
 }
+
+/**
+ * sysfs_path_is_file: Check if the path supplied points to a file
+ * @path: path to validate
+ * Returns 0 if path points to file, 1 otherwise
+ */
+int sysfs_path_is_file(const unsigned char *path)
+{
+	struct stat astats;
+
+	if (path == NULL) {
+		errno = EINVAL;
+		return 1;
+	}
+	if ((lstat(path, &astats)) != 0) {
+		dprintf("stat() failed\n");
+		return 1;
+	}
+	if (S_ISREG(astats.st_mode))
+		return 0;
+		
+	return 1;
+}