1 files changed, 685 insertions, 0 deletions

diff --git a/drivers/block/genhd.c b/drivers/block/genhd.c
new file mode 100644
index 000000000000..ab4db71375e0
--- /dev/null
+++ b/drivers/block/genhd.c
@@ -0,0 +1,685 @@
+/*
+ *  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>
+
+#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)
+{
+        struct blk_major_name *n;
+        int i, len;
+
+        len = sprintf(p, "\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)
+                        len += sprintf(p+len, "%3d %s\n",
+                                       n->major, n->name);
+        }
+        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 = 0;
+
+        if (disk_attr->show)
+                ret = disk_attr->show(disk,page);
+        return ret;
+}
+
+static struct sysfs_ops disk_sysfs_ops = {
+        .show   = &disk_attr_show,
+};
+
+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, reads), disk_stat_read(disk, read_merges),
+                (unsigned long long)disk_stat_read(disk, read_sectors),
+                jiffies_to_msecs(disk_stat_read(disk, read_ticks)),
+                disk_stat_read(disk, writes), 
+                disk_stat_read(disk, write_merges),
+                (unsigned long long)disk_stat_read(disk, write_sectors),
+                jiffies_to_msecs(disk_stat_read(disk, write_ticks)),
+                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_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_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, reads), disk_stat_read(gp, read_merges),
+                (unsigned long long)disk_stat_read(gp, read_sectors),
+                jiffies_to_msecs(disk_stat_read(gp, read_ticks)),
+                disk_stat_read(gp, writes), disk_stat_read(gp, write_merges),
+                (unsigned long long)disk_stat_read(gp, write_sectors),
+                jiffies_to_msecs(disk_stat_read(gp, write_ticks)),
+                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->reads, hd->read_sectors,
+                                hd->writes, hd->write_sectors);
+        }
+ 
+        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)
+{
+        struct gendisk *disk = kmalloc(sizeof(struct gendisk), GFP_KERNEL);
+        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(size, GFP_KERNEL);
+                        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);
+
+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) {
+                res = __invalidate_device(bdev, 1);
+                bdput(bdev);
+        }
+        return res;
+}
+
+EXPORT_SYMBOL(invalidate_partition);