Added sysfs_block.c

5 files changed, 319 insertions, 7 deletions

diff --git a/lib/Makefile.am b/lib/Makefile.am
index d343f01..2b5049a 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -1,5 +1,5 @@
 lib_LIBRARIES = libsysfs.a
 libsysfs_a_SOURCES = sysfs_utils.c sysfs_dir.c sysfs_bus.c sysfs_class.c \
-	sysfs_device.c sysfs_driver.c sysfs.h dlist.c
+	sysfs_device.c sysfs_driver.c sysfs_block.c sysfs.h dlist.c
 INCLUDES = -I../include
 
diff --git a/lib/Makefile.in b/lib/Makefile.in
index a2e859e..2ecbd5f 100644
--- a/lib/Makefile.in
+++ b/lib/Makefile.in
@@ -77,7 +77,7 @@ am__quote = @am__quote@
 install_sh = @install_sh@
 lib_LIBRARIES = libsysfs.a
 libsysfs_a_SOURCES = sysfs_utils.c sysfs_dir.c sysfs_bus.c sysfs_class.c \
-	sysfs_device.c sysfs_driver.c sysfs.h dlist.c
+	sysfs_device.c sysfs_driver.c sysfs_block.c sysfs.h dlist.c
 
 INCLUDES = -I../include
 subdir = lib
@@ -90,7 +90,8 @@ libsysfs_a_AR = $(AR) cru
 libsysfs_a_LIBADD =
 am_libsysfs_a_OBJECTS = sysfs_utils.$(OBJEXT) sysfs_dir.$(OBJEXT) \
 	sysfs_bus.$(OBJEXT) sysfs_class.$(OBJEXT) \
-	sysfs_device.$(OBJEXT) sysfs_driver.$(OBJEXT) dlist.$(OBJEXT)
+	sysfs_device.$(OBJEXT) sysfs_driver.$(OBJEXT) \
+	sysfs_block.$(OBJEXT) dlist.$(OBJEXT)
 libsysfs_a_OBJECTS = $(am_libsysfs_a_OBJECTS)
 
 DEFS = @DEFS@
@@ -100,8 +101,8 @@ LDFLAGS = @LDFLAGS@
 LIBS = @LIBS@
 depcomp = $(SHELL) $(top_srcdir)/depcomp
 am__depfiles_maybe = depfiles
-@AMDEP_TRUE@DEP_FILES = ./$(DEPDIR)/dlist.Po ./$(DEPDIR)/sysfs_bus.Po \
-@AMDEP_TRUE@	./$(DEPDIR)/sysfs_class.Po \
+@AMDEP_TRUE@DEP_FILES = ./$(DEPDIR)/dlist.Po ./$(DEPDIR)/sysfs_block.Po \
+@AMDEP_TRUE@	./$(DEPDIR)/sysfs_bus.Po ./$(DEPDIR)/sysfs_class.Po \
 @AMDEP_TRUE@	./$(DEPDIR)/sysfs_device.Po \
 @AMDEP_TRUE@	./$(DEPDIR)/sysfs_dir.Po \
 @AMDEP_TRUE@	./$(DEPDIR)/sysfs_driver.Po \
@@ -168,6 +169,7 @@ distclean-compile:
 	-rm -f *.tab.c
 
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/dlist.Po@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/sysfs_block.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/sysfs_bus.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/sysfs_class.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/sysfs_device.Po@am__quote@
diff --git a/lib/sysfs_block.c b/lib/sysfs_block.c
new file mode 100644
index 0000000..601f575
--- /dev/null
+++ b/lib/sysfs_block.c
@@ -0,0 +1,309 @@
+/*
+ * sysfs_block.c
+ *
+ * Generic block utility functions for libsysfs
+ *
+ * Copyright (C) IBM Corp. 2003
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Lesser General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2.1 of the License, or (at your option) any later version.
+ *
+ *  This library is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ *  Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public
+ *  License along with this library; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+/*
+ * NOTES:
+ * 	Write functions to:
+ * 		Device major/minor given a device
+ * 		As of now, only the "block" device has writable attribs. 
+ * 			Library has to take care of navigating to the attribute
+ * 			(may be at various directory levels)
+ */
+
+#include "libsysfs.h"
+#include "sysfs.h"
+
+void sysfs_del_partition(void *partition)
+{
+	sysfs_close_block_partition((struct sysfs_block_partition *)partition);
+}
+
+/**
+ * sysfs_close_block_partition: closes a block partition
+ * @partition: sysfs_block_partition to close
+ */
+void sysfs_close_block_partition(struct sysfs_block_partition *partition)
+{
+	if (partition != NULL) {
+		if (partition->directory != NULL)
+/*	reuse sysfs_dir from the earlier structure - just set it to NULL here 
+ *	free it while closing sysfs_block_device->directory
+ * 		sysfs_close_directory(partition->directory);*/
+			partition->directory = NULL;
+	}
+}
+
+/**
+ * sysfs_close_block_device: closes a sysfs_block_device
+ * @block: sysfs_block_device structure
+ */
+void sysfs_close_block_device(struct sysfs_block_device *block)
+{
+	if (block != NULL) {
+		if (block->directory != NULL) 
+			sysfs_close_directory(block->directory);
+		if (block->device != NULL) 
+			sysfs_close_device(block->device);
+		if (block->partitions  != NULL)
+			dlist_destroy(block->partitions);
+	}
+}
+
+/**
+ * alloc_block_device: allocate a sysfs_block_device
+ * returns sysfs_block_device or NULL
+ */
+static struct sysfs_block_device *alloc_block_device()
+{
+	return (struct sysfs_block_device *)
+		calloc(1, sizeof(struct sysfs_block_device));
+}
+
+/**
+ * open_block_dir: opens a sysfs block directory
+ * returns sysfs_directory on success or NULL on error
+ */
+static struct sysfs_directory *open_block_dir(const unsigned char *name)
+{
+	unsigned char path[SYSFS_PATH_MAX];
+	struct sysfs_directory *directory = NULL;
+
+	if (name == NULL) {
+		errno = EINVAL;
+		return NULL;
+	}
+
+	memset(path, 0, SYSFS_PATH_MAX);
+	if ((sysfs_get_mnt_path(path, SYSFS_PATH_MAX)) != 0) {
+		dprintf("Error getting sysfs mount path\n");
+		return NULL;
+	}
+
+	strcat(path, SYSFS_BLOCK_DIR);
+	strcat(path, "/");
+	strcat(path, name);
+	directory = sysfs_open_directory(path);
+	if (directory == NULL) {
+		dprintf("Block device %s not supported on this system",	name);
+		return NULL;
+	}
+	if ((sysfs_read_directory(directory)) != 0) {
+		dprintf("Error reading directory %s\n", directory->path);
+		sysfs_close_directory(directory);
+		return NULL;
+	}
+	sysfs_read_all_subdirs(directory);
+
+	return directory;
+}
+
+/**
+ * alloc_block_partition: alloc a sysfs_block_partition structure
+ */
+static struct sysfs_block_partition *alloc_block_partition(void)
+{
+	return(struct sysfs_block_partition *)
+			calloc(1, sizeof(struct sysfs_block_partition));
+}
+
+/**
+ * get_all_block_devices: Retrieves details of block directory
+ * @block: sysfs_block_device for which details are required
+ * returns 0 on success, -1 on failure
+ */
+static int get_all_block_devices(struct sysfs_block_device *block)
+{
+	struct sysfs_directory *cur = NULL;
+	struct sysfs_block_partition *part = NULL;
+
+	if (block == NULL || block->directory == NULL) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	dlist_for_each_data(block->directory->subdirs, cur, 
+						struct sysfs_directory) {
+		switch(strcmp(cur->name, SYSFS_QUEUE_NAME)) {
+			case 0:	/* this is the "queue" directory */
+				if ((sysfs_read_directory(cur)) < 0) {
+					dprintf("Error reading directory %s\n",
+							cur->path);
+					return -1;
+				}
+				break;
+			default: /* these are the partitions */
+				part = alloc_block_partition();
+				if (part == NULL) {
+					perror("calloc");
+					return -1;
+				}
+				part->directory = cur;
+				strcpy(part->name, cur->name);
+				if (block->partitions == NULL) 
+					block->partitions = 
+						dlist_new_with_delete
+						(sizeof(struct 
+							sysfs_block_partition),
+							 sysfs_del_partition);
+				dlist_unshift(block->partitions, part);
+				break;
+		}
+	}
+	return 0;		
+}
+
+/**
+ * sysfs_open_block_device: opens the specific block device and all its related
+ * 		details as partitions, etc
+ * returns sysfs_block_device struct on success and NULL on error
+ */
+struct sysfs_block_device *sysfs_open_block_device(unsigned char *name)
+{
+	struct sysfs_block_device *block = NULL;
+	struct sysfs_directory *blockdir = NULL;
+	struct sysfs_link *curlink = NULL;
+
+	if (name == NULL) {
+		errno = EINVAL;
+		return NULL;
+	}
+
+	block = alloc_block_device();
+	if (block == NULL) {
+		perror("calloc");
+		return NULL;
+	}
+	strcpy(block->name, name);
+	blockdir = open_block_dir(name);
+	if (blockdir == NULL) {
+		sysfs_close_block_device(block);
+		return NULL;
+	}
+	strcpy(block->path, blockdir->path);
+	block->directory = blockdir;
+	if ((get_all_block_devices(block)) != 0) {
+		dprintf("Error retrieving devices for block %s\n", name);
+		sysfs_close_block_device(block);
+		return NULL;
+	}
+	/* check if the "block" device has a link to the physical device */
+	if (block->directory->links != NULL) {
+		dlist_for_each_data(block->directory->links, curlink,
+				struct sysfs_link) {
+			block->device = sysfs_open_device(curlink->target);
+			if (block->device == NULL) {
+				dprintf("Error opening device at %s\n",
+						curlink->target);
+			}
+		}
+	}
+
+	return block;
+}
+
+/** 
+ * sysfs_get_blockdev_attributes: returns attributes for the block device
+ * @block: block device for which attribs are to be returned
+ */
+struct dlist *sysfs_get_blockdev_attributes(struct sysfs_block_device *block)
+{
+	if (block == NULL || block->directory == NULL) 
+		return NULL;
+	
+	return(block->directory->attributes);
+}
+		
+/** 
+ * sysfs_get_partition_attributes: returns attributes for the block 
+ * 					device partition
+ * @block: block device partition for which attribs are to be returned
+ */
+struct dlist *sysfs_get_partition_attributes
+				(struct sysfs_block_partition *part)
+{
+	if (part == NULL || part->directory == NULL) 
+		return NULL;
+
+	return(part->directory->attributes);
+}
+
+/**
+ * sysfs_get_queue_attributes: returns attributes for the block device's
+ * 				QUEUE parameters. Used to set #of queued
+ * 				requests as well as the choice of IO
+ * 				scheduler
+ * @block: block device for which the attributes are needed.
+ */
+struct dlist *sysfs_get_queue_attributes(struct sysfs_block_device *block)
+{
+	struct dlist *list = NULL;
+	struct sysfs_directory *dir = NULL;
+	unsigned int found = 0;
+
+	dlist_for_each_data(block->directory->subdirs, dir, 
+					struct sysfs_directory) {
+		if ((strcmp(dir->name, SYSFS_QUEUE_NAME)) != 0) 
+			continue;
+		else 
+			return (dir->attributes);
+	}
+	return NULL;
+}
+
+/**
+ * sysfs_get_iosched_attributes: returns attributes for the block device's
+ * 				IOSCHED parameters for the given device
+ * @block: block device for which the attributes are needed
+ * returns a dlist of iosched attributes. 
+ */
+struct dlist *sysfs_get_iosched_attributes(struct sysfs_block_device *block)
+{
+	struct dlist *list = NULL;
+	struct sysfs_directory *dir = NULL, *new = NULL;
+	unsigned int found = 0;
+	
+	dlist_for_each_data(block->directory->subdirs, dir, 
+					struct sysfs_directory) {
+		if ((strcmp(dir->name, SYSFS_QUEUE_NAME)) != 0) 
+			continue;
+		else {
+			found = 1;
+			break;
+		}
+	}
+	if (found) {
+		/* 
+		 * this is the queue directory - read this and the
+		 * iosched directory too
+		 */
+		dlist_for_each_data(dir->subdirs, new, 
+						struct sysfs_directory) {
+			if ((strcmp(new->name, SYSFS_IOSCHED_NAME)) == 0) 
+				if ((sysfs_read_directory(new)) == 0) 
+					return new->attributes;
+		}
+	}
+	dprintf("IOSCHED attributes not found\n");
+	return NULL;
+}
+			
diff --git a/lib/sysfs_class.c b/lib/sysfs_class.c
index 6c969b5..9172a1e 100644
--- a/lib/sysfs_class.c
+++ b/lib/sysfs_class.c
@@ -264,7 +264,7 @@ struct sysfs_class *sysfs_open_class(const unsigned char *name)
 
 	cls = alloc_class();
 	if (cls == NULL) {
-		perror("malloc");
+		perror("calloc");
 		return NULL;
 	}
 	strcpy(cls->name, name);	
diff --git a/lib/sysfs_dir.c b/lib/sysfs_dir.c
index 1d730e7..46ebd52 100644
--- a/lib/sysfs_dir.c
+++ b/lib/sysfs_dir.c
@@ -525,10 +525,11 @@ int sysfs_read_directory(struct sysfs_directory *sysdir)
 				}
 			}
 			                        
-			if (sysdir->attributes == NULL)
+			if (sysdir->attributes == NULL) {
 				sysdir->attributes = dlist_new_with_delete
 					(sizeof(struct sysfs_attribute),
 					 		sysfs_del_attribute);
+			}
 			dlist_unshift(sysdir->attributes, attr);
 		} else if (S_ISDIR(astats.st_mode)) {
 			subdir = sysfs_open_directory(file_path);