[BLOCK] Move all core block layer code to new block/ directory

drivers/block/ is right now a mix of core and driver parts. Lets move
the core parts to a new top level directory. Al will move the fs/
related block parts to block/ next.

Signed-off-by: Jens Axboe <axboe@suse.de>

1 files changed, 726 insertions, 0 deletions

diff --git a/block/genhd.c b/block/genhd.c
new file mode 100644
index 000000000000..54aec4a1ae13
--- /dev/null
+++ b/block/genhd.c
@@ -0,0 +1,726 @@
+/*
+ *  gendisk handling
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/genhd.h>
+#include <linux/kernel.h>
+#include <linux/blkdev.h>
+#include <linux/init.h>
+#include <linux/spinlock.h>
+#include <linux/seq_file.h>
+#include <linux/slab.h>
+#include <linux/kmod.h>
+#include <linux/kobj_map.h>
+#include <linux/buffer_head.h>
+
+#define MAX_PROBE_HASH 255	/* random */
+
+static struct subsystem block_subsys;
+
+static DECLARE_MUTEX(block_subsys_sem);
+
+/*
+ * Can be deleted altogether. Later.
+ *
+ */
+static struct blk_major_name {
+	struct blk_major_name *next;
+	int major;
+	char name[16];
+} *major_names[MAX_PROBE_HASH];
+
+/* index in the above - for now: assume no multimajor ranges */
+static inline int major_to_index(int major)
+{
+	return major % MAX_PROBE_HASH;
+}
+
+#ifdef CONFIG_PROC_FS
+/* get block device names in somewhat random order */
+int get_blkdev_list(char *p, int used)
+{
+	struct blk_major_name *n;
+	int i, len;
+
+	len = snprintf(p, (PAGE_SIZE-used), "\nBlock devices:\n");
+
+	down(&block_subsys_sem);
+	for (i = 0; i < ARRAY_SIZE(major_names); i++) {
+		for (n = major_names[i]; n; n = n->next) {
+			/*
+			 * If the curent string plus the 5 extra characters
+			 * in the line would run us off the page, then we're done
+			 */
+			if ((len + used + strlen(n->name) + 5) >= PAGE_SIZE)
+				goto page_full;
+			len += sprintf(p+len, "%3d %s\n",
+				       n->major, n->name);
+		}
+	}
+page_full:
+	up(&block_subsys_sem);
+
+	return len;
+}
+#endif
+
+int register_blkdev(unsigned int major, const char *name)
+{
+	struct blk_major_name **n, *p;
+	int index, ret = 0;
+
+	down(&block_subsys_sem);
+
+	/* temporary */
+	if (major == 0) {
+		for (index = ARRAY_SIZE(major_names)-1; index > 0; index--) {
+			if (major_names[index] == NULL)
+				break;
+		}
+
+		if (index == 0) {
+			printk("register_blkdev: failed to get major for %s\n",
+			       name);
+			ret = -EBUSY;
+			goto out;
+		}
+		major = index;
+		ret = major;
+	}
+
+	p = kmalloc(sizeof(struct blk_major_name), GFP_KERNEL);
+	if (p == NULL) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	p->major = major;
+	strlcpy(p->name, name, sizeof(p->name));
+	p->next = NULL;
+	index = major_to_index(major);
+
+	for (n = &major_names[index]; *n; n = &(*n)->next) {
+		if ((*n)->major == major)
+			break;
+	}
+	if (!*n)
+		*n = p;
+	else
+		ret = -EBUSY;
+
+	if (ret < 0) {
+		printk("register_blkdev: cannot get major %d for %s\n",
+		       major, name);
+		kfree(p);
+	}
+out:
+	up(&block_subsys_sem);
+	return ret;
+}
+
+EXPORT_SYMBOL(register_blkdev);
+
+/* todo: make void - error printk here */
+int unregister_blkdev(unsigned int major, const char *name)
+{
+	struct blk_major_name **n;
+	struct blk_major_name *p = NULL;
+	int index = major_to_index(major);
+	int ret = 0;
+
+	down(&block_subsys_sem);
+	for (n = &major_names[index]; *n; n = &(*n)->next)
+		if ((*n)->major == major)
+			break;
+	if (!*n || strcmp((*n)->name, name))
+		ret = -EINVAL;
+	else {
+		p = *n;
+		*n = p->next;
+	}
+	up(&block_subsys_sem);
+	kfree(p);
+
+	return ret;
+}
+
+EXPORT_SYMBOL(unregister_blkdev);
+
+static struct kobj_map *bdev_map;
+
+/*
+ * Register device numbers dev..(dev+range-1)
+ * range must be nonzero
+ * The hash chain is sorted on range, so that subranges can override.
+ */
+void blk_register_region(dev_t dev, unsigned long range, struct module *module,
+			 struct kobject *(*probe)(dev_t, int *, void *),
+			 int (*lock)(dev_t, void *), void *data)
+{
+	kobj_map(bdev_map, dev, range, module, probe, lock, data);
+}
+
+EXPORT_SYMBOL(blk_register_region);
+
+void blk_unregister_region(dev_t dev, unsigned long range)
+{
+	kobj_unmap(bdev_map, dev, range);
+}
+
+EXPORT_SYMBOL(blk_unregister_region);
+
+static struct kobject *exact_match(dev_t dev, int *part, void *data)
+{
+	struct gendisk *p = data;
+	return &p->kobj;
+}
+
+static int exact_lock(dev_t dev, void *data)
+{
+	struct gendisk *p = data;
+
+	if (!get_disk(p))
+		return -1;
+	return 0;
+}
+
+/**
+ * add_disk - add partitioning information to kernel list
+ * @disk: per-device partitioning information
+ *
+ * This function registers the partitioning information in @disk
+ * with the kernel.
+ */
+void add_disk(struct gendisk *disk)
+{
+	disk->flags |= GENHD_FL_UP;
+	blk_register_region(MKDEV(disk->major, disk->first_minor),
+			    disk->minors, NULL, exact_match, exact_lock, disk);
+	register_disk(disk);
+	blk_register_queue(disk);
+}
+
+EXPORT_SYMBOL(add_disk);
+EXPORT_SYMBOL(del_gendisk);	/* in partitions/check.c */
+
+void unlink_gendisk(struct gendisk *disk)
+{
+	blk_unregister_queue(disk);
+	blk_unregister_region(MKDEV(disk->major, disk->first_minor),
+			      disk->minors);
+}
+
+#define to_disk(obj) container_of(obj,struct gendisk,kobj)
+
+/**
+ * get_gendisk - get partitioning information for a given device
+ * @dev: device to get partitioning information for
+ *
+ * This function gets the structure containing partitioning
+ * information for the given device @dev.
+ */
+struct gendisk *get_gendisk(dev_t dev, int *part)
+{
+	struct kobject *kobj = kobj_lookup(bdev_map, dev, part);
+	return  kobj ? to_disk(kobj) : NULL;
+}
+
+#ifdef CONFIG_PROC_FS
+/* iterator */
+static void *part_start(struct seq_file *part, loff_t *pos)
+{
+	struct list_head *p;
+	loff_t l = *pos;
+
+	down(&block_subsys_sem);
+	list_for_each(p, &block_subsys.kset.list)
+		if (!l--)
+			return list_entry(p, struct gendisk, kobj.entry);
+	return NULL;
+}
+
+static void *part_next(struct seq_file *part, void *v, loff_t *pos)
+{
+	struct list_head *p = ((struct gendisk *)v)->kobj.entry.next;
+	++*pos;
+	return p==&block_subsys.kset.list ? NULL : 
+		list_entry(p, struct gendisk, kobj.entry);
+}
+
+static void part_stop(struct seq_file *part, void *v)
+{
+	up(&block_subsys_sem);
+}
+
+static int show_partition(struct seq_file *part, void *v)
+{
+	struct gendisk *sgp = v;
+	int n;
+	char buf[BDEVNAME_SIZE];
+
+	if (&sgp->kobj.entry == block_subsys.kset.list.next)
+		seq_puts(part, "major minor  #blocks  name\n\n");
+
+	/* Don't show non-partitionable removeable devices or empty devices */
+	if (!get_capacity(sgp) ||
+			(sgp->minors == 1 && (sgp->flags & GENHD_FL_REMOVABLE)))
+		return 0;
+	if (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO)
+		return 0;
+
+	/* show the full disk and all non-0 size partitions of it */
+	seq_printf(part, "%4d  %4d %10llu %s\n",
+		sgp->major, sgp->first_minor,
+		(unsigned long long)get_capacity(sgp) >> 1,
+		disk_name(sgp, 0, buf));
+	for (n = 0; n < sgp->minors - 1; n++) {
+		if (!sgp->part[n])
+			continue;
+		if (sgp->part[n]->nr_sects == 0)
+			continue;
+		seq_printf(part, "%4d  %4d %10llu %s\n",
+			sgp->major, n + 1 + sgp->first_minor,
+			(unsigned long long)sgp->part[n]->nr_sects >> 1 ,
+			disk_name(sgp, n + 1, buf));
+	}
+
+	return 0;
+}
+
+struct seq_operations partitions_op = {
+	.start =part_start,
+	.next =	part_next,
+	.stop =	part_stop,
+	.show =	show_partition
+};
+#endif
+
+
+extern int blk_dev_init(void);
+
+static struct kobject *base_probe(dev_t dev, int *part, void *data)
+{
+	if (request_module("block-major-%d-%d", MAJOR(dev), MINOR(dev)) > 0)
+		/* Make old-style 2.4 aliases work */
+		request_module("block-major-%d", MAJOR(dev));
+	return NULL;
+}
+
+static int __init genhd_device_init(void)
+{
+	bdev_map = kobj_map_init(base_probe, &block_subsys_sem);
+	blk_dev_init();
+	subsystem_register(&block_subsys);
+	return 0;
+}
+
+subsys_initcall(genhd_device_init);
+
+
+
+/*
+ * kobject & sysfs bindings for block devices
+ */
+static ssize_t disk_attr_show(struct kobject *kobj, struct attribute *attr,
+			      char *page)
+{
+	struct gendisk *disk = to_disk(kobj);
+	struct disk_attribute *disk_attr =
+		container_of(attr,struct disk_attribute,attr);
+	ssize_t ret = -EIO;
+
+	if (disk_attr->show)
+		ret = disk_attr->show(disk,page);
+	return ret;
+}
+
+static ssize_t disk_attr_store(struct kobject * kobj, struct attribute * attr,
+			       const char *page, size_t count)
+{
+	struct gendisk *disk = to_disk(kobj);
+	struct disk_attribute *disk_attr =
+		container_of(attr,struct disk_attribute,attr);
+	ssize_t ret = 0;
+
+	if (disk_attr->store)
+		ret = disk_attr->store(disk, page, count);
+	return ret;
+}
+
+static struct sysfs_ops disk_sysfs_ops = {
+	.show	= &disk_attr_show,
+	.store	= &disk_attr_store,
+};
+
+static ssize_t disk_uevent_store(struct gendisk * disk,
+				 const char *buf, size_t count)
+{
+	kobject_hotplug(&disk->kobj, KOBJ_ADD);
+	return count;
+}
+static ssize_t disk_dev_read(struct gendisk * disk, char *page)
+{
+	dev_t base = MKDEV(disk->major, disk->first_minor); 
+	return print_dev_t(page, base);
+}
+static ssize_t disk_range_read(struct gendisk * disk, char *page)
+{
+	return sprintf(page, "%d\n", disk->minors);
+}
+static ssize_t disk_removable_read(struct gendisk * disk, char *page)
+{
+	return sprintf(page, "%d\n",
+		       (disk->flags & GENHD_FL_REMOVABLE ? 1 : 0));
+
+}
+static ssize_t disk_size_read(struct gendisk * disk, char *page)
+{
+	return sprintf(page, "%llu\n", (unsigned long long)get_capacity(disk));
+}
+
+static ssize_t disk_stats_read(struct gendisk * disk, char *page)
+{
+	preempt_disable();
+	disk_round_stats(disk);
+	preempt_enable();
+	return sprintf(page,
+		"%8u %8u %8llu %8u "
+		"%8u %8u %8llu %8u "
+		"%8u %8u %8u"
+		"\n",
+		disk_stat_read(disk, ios[0]), disk_stat_read(disk, merges[0]),
+		(unsigned long long)disk_stat_read(disk, sectors[0]),
+		jiffies_to_msecs(disk_stat_read(disk, ticks[0])),
+		disk_stat_read(disk, ios[1]), disk_stat_read(disk, merges[1]),
+		(unsigned long long)disk_stat_read(disk, sectors[1]),
+		jiffies_to_msecs(disk_stat_read(disk, ticks[1])),
+		disk->in_flight,
+		jiffies_to_msecs(disk_stat_read(disk, io_ticks)),
+		jiffies_to_msecs(disk_stat_read(disk, time_in_queue)));
+}
+static struct disk_attribute disk_attr_uevent = {
+	.attr = {.name = "uevent", .mode = S_IWUSR },
+	.store	= disk_uevent_store
+};
+static struct disk_attribute disk_attr_dev = {
+	.attr = {.name = "dev", .mode = S_IRUGO },
+	.show	= disk_dev_read
+};
+static struct disk_attribute disk_attr_range = {
+	.attr = {.name = "range", .mode = S_IRUGO },
+	.show	= disk_range_read
+};
+static struct disk_attribute disk_attr_removable = {
+	.attr = {.name = "removable", .mode = S_IRUGO },
+	.show	= disk_removable_read
+};
+static struct disk_attribute disk_attr_size = {
+	.attr = {.name = "size", .mode = S_IRUGO },
+	.show	= disk_size_read
+};
+static struct disk_attribute disk_attr_stat = {
+	.attr = {.name = "stat", .mode = S_IRUGO },
+	.show	= disk_stats_read
+};
+
+static struct attribute * default_attrs[] = {
+	&disk_attr_uevent.attr,
+	&disk_attr_dev.attr,
+	&disk_attr_range.attr,
+	&disk_attr_removable.attr,
+	&disk_attr_size.attr,
+	&disk_attr_stat.attr,
+	NULL,
+};
+
+static void disk_release(struct kobject * kobj)
+{
+	struct gendisk *disk = to_disk(kobj);
+	kfree(disk->random);
+	kfree(disk->part);
+	free_disk_stats(disk);
+	kfree(disk);
+}
+
+static struct kobj_type ktype_block = {
+	.release	= disk_release,
+	.sysfs_ops	= &disk_sysfs_ops,
+	.default_attrs	= default_attrs,
+};
+
+extern struct kobj_type ktype_part;
+
+static int block_hotplug_filter(struct kset *kset, struct kobject *kobj)
+{
+	struct kobj_type *ktype = get_ktype(kobj);
+
+	return ((ktype == &ktype_block) || (ktype == &ktype_part));
+}
+
+static int block_hotplug(struct kset *kset, struct kobject *kobj, char **envp,
+			 int num_envp, char *buffer, int buffer_size)
+{
+	struct kobj_type *ktype = get_ktype(kobj);
+	struct device *physdev;
+	struct gendisk *disk;
+	struct hd_struct *part;
+	int length = 0;
+	int i = 0;
+
+	if (ktype == &ktype_block) {
+		disk = container_of(kobj, struct gendisk, kobj);
+		add_hotplug_env_var(envp, num_envp, &i, buffer, buffer_size,
+				    &length, "MINOR=%u", disk->first_minor);
+	} else if (ktype == &ktype_part) {
+		disk = container_of(kobj->parent, struct gendisk, kobj);
+		part = container_of(kobj, struct hd_struct, kobj);
+		add_hotplug_env_var(envp, num_envp, &i, buffer, buffer_size,
+				    &length, "MINOR=%u",
+				    disk->first_minor + part->partno);
+	} else
+		return 0;
+
+	add_hotplug_env_var(envp, num_envp, &i, buffer, buffer_size, &length,
+			    "MAJOR=%u", disk->major);
+
+	/* add physical device, backing this device  */
+	physdev = disk->driverfs_dev;
+	if (physdev) {
+		char *path = kobject_get_path(&physdev->kobj, GFP_KERNEL);
+
+		add_hotplug_env_var(envp, num_envp, &i, buffer, buffer_size,
+				    &length, "PHYSDEVPATH=%s", path);
+		kfree(path);
+
+		if (physdev->bus)
+			add_hotplug_env_var(envp, num_envp, &i,
+					    buffer, buffer_size, &length,
+					    "PHYSDEVBUS=%s",
+					    physdev->bus->name);
+
+		if (physdev->driver)
+			add_hotplug_env_var(envp, num_envp, &i,
+					    buffer, buffer_size, &length,
+					    "PHYSDEVDRIVER=%s",
+					    physdev->driver->name);
+	}
+
+	/* terminate, set to next free slot, shrink available space */
+	envp[i] = NULL;
+	envp = &envp[i];
+	num_envp -= i;
+	buffer = &buffer[length];
+	buffer_size -= length;
+
+	return 0;
+}
+
+static struct kset_hotplug_ops block_hotplug_ops = {
+	.filter		= block_hotplug_filter,
+	.hotplug	= block_hotplug,
+};
+
+/* declare block_subsys. */
+static decl_subsys(block, &ktype_block, &block_hotplug_ops);
+
+
+/*
+ * aggregate disk stat collector.  Uses the same stats that the sysfs
+ * entries do, above, but makes them available through one seq_file.
+ * Watching a few disks may be efficient through sysfs, but watching
+ * all of them will be more efficient through this interface.
+ *
+ * The output looks suspiciously like /proc/partitions with a bunch of
+ * extra fields.
+ */
+
+/* iterator */
+static void *diskstats_start(struct seq_file *part, loff_t *pos)
+{
+	loff_t k = *pos;
+	struct list_head *p;
+
+	down(&block_subsys_sem);
+	list_for_each(p, &block_subsys.kset.list)
+		if (!k--)
+			return list_entry(p, struct gendisk, kobj.entry);
+	return NULL;
+}
+
+static void *diskstats_next(struct seq_file *part, void *v, loff_t *pos)
+{
+	struct list_head *p = ((struct gendisk *)v)->kobj.entry.next;
+	++*pos;
+	return p==&block_subsys.kset.list ? NULL :
+		list_entry(p, struct gendisk, kobj.entry);
+}
+
+static void diskstats_stop(struct seq_file *part, void *v)
+{
+	up(&block_subsys_sem);
+}
+
+static int diskstats_show(struct seq_file *s, void *v)
+{
+	struct gendisk *gp = v;
+	char buf[BDEVNAME_SIZE];
+	int n = 0;
+
+	/*
+	if (&sgp->kobj.entry == block_subsys.kset.list.next)
+		seq_puts(s,	"major minor name"
+				"     rio rmerge rsect ruse wio wmerge "
+				"wsect wuse running use aveq"
+				"\n\n");
+	*/
+ 
+	preempt_disable();
+	disk_round_stats(gp);
+	preempt_enable();
+	seq_printf(s, "%4d %4d %s %u %u %llu %u %u %u %llu %u %u %u %u\n",
+		gp->major, n + gp->first_minor, disk_name(gp, n, buf),
+		disk_stat_read(gp, ios[0]), disk_stat_read(gp, merges[0]),
+		(unsigned long long)disk_stat_read(gp, sectors[0]),
+		jiffies_to_msecs(disk_stat_read(gp, ticks[0])),
+		disk_stat_read(gp, ios[1]), disk_stat_read(gp, merges[1]),
+		(unsigned long long)disk_stat_read(gp, sectors[1]),
+		jiffies_to_msecs(disk_stat_read(gp, ticks[1])),
+		gp->in_flight,
+		jiffies_to_msecs(disk_stat_read(gp, io_ticks)),
+		jiffies_to_msecs(disk_stat_read(gp, time_in_queue)));
+
+	/* now show all non-0 size partitions of it */
+	for (n = 0; n < gp->minors - 1; n++) {
+		struct hd_struct *hd = gp->part[n];
+
+		if (hd && hd->nr_sects)
+			seq_printf(s, "%4d %4d %s %u %u %u %u\n",
+				gp->major, n + gp->first_minor + 1,
+				disk_name(gp, n + 1, buf),
+				hd->ios[0], hd->sectors[0],
+				hd->ios[1], hd->sectors[1]);
+	}
+ 
+	return 0;
+}
+
+struct seq_operations diskstats_op = {
+	.start	= diskstats_start,
+	.next	= diskstats_next,
+	.stop	= diskstats_stop,
+	.show	= diskstats_show
+};
+
+struct gendisk *alloc_disk(int minors)
+{
+	return alloc_disk_node(minors, -1);
+}
+
+struct gendisk *alloc_disk_node(int minors, int node_id)
+{
+	struct gendisk *disk;
+
+	disk = kmalloc_node(sizeof(struct gendisk), GFP_KERNEL, node_id);
+	if (disk) {
+		memset(disk, 0, sizeof(struct gendisk));
+		if (!init_disk_stats(disk)) {
+			kfree(disk);
+			return NULL;
+		}
+		if (minors > 1) {
+			int size = (minors - 1) * sizeof(struct hd_struct *);
+			disk->part = kmalloc_node(size, GFP_KERNEL, node_id);
+			if (!disk->part) {
+				kfree(disk);
+				return NULL;
+			}
+			memset(disk->part, 0, size);
+		}
+		disk->minors = minors;
+		kobj_set_kset_s(disk,block_subsys);
+		kobject_init(&disk->kobj);
+		rand_initialize_disk(disk);
+	}
+	return disk;
+}
+
+EXPORT_SYMBOL(alloc_disk);
+EXPORT_SYMBOL(alloc_disk_node);
+
+struct kobject *get_disk(struct gendisk *disk)
+{
+	struct module *owner;
+	struct kobject *kobj;
+
+	if (!disk->fops)
+		return NULL;
+	owner = disk->fops->owner;
+	if (owner && !try_module_get(owner))
+		return NULL;
+	kobj = kobject_get(&disk->kobj);
+	if (kobj == NULL) {
+		module_put(owner);
+		return NULL;
+	}
+	return kobj;
+
+}
+
+EXPORT_SYMBOL(get_disk);
+
+void put_disk(struct gendisk *disk)
+{
+	if (disk)
+		kobject_put(&disk->kobj);
+}
+
+EXPORT_SYMBOL(put_disk);
+
+void set_device_ro(struct block_device *bdev, int flag)
+{
+	if (bdev->bd_contains != bdev)
+		bdev->bd_part->policy = flag;
+	else
+		bdev->bd_disk->policy = flag;
+}
+
+EXPORT_SYMBOL(set_device_ro);
+
+void set_disk_ro(struct gendisk *disk, int flag)
+{
+	int i;
+	disk->policy = flag;
+	for (i = 0; i < disk->minors - 1; i++)
+		if (disk->part[i]) disk->part[i]->policy = flag;
+}
+
+EXPORT_SYMBOL(set_disk_ro);
+
+int bdev_read_only(struct block_device *bdev)
+{
+	if (!bdev)
+		return 0;
+	else if (bdev->bd_contains != bdev)
+		return bdev->bd_part->policy;
+	else
+		return bdev->bd_disk->policy;
+}
+
+EXPORT_SYMBOL(bdev_read_only);
+
+int invalidate_partition(struct gendisk *disk, int index)
+{
+	int res = 0;
+	struct block_device *bdev = bdget_disk(disk, index);
+	if (bdev) {
+		fsync_bdev(bdev);
+		res = __invalidate_device(bdev);
+		bdput(bdev);
+	}
+	return res;
+}
+
+EXPORT_SYMBOL(invalidate_partition);