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-rw-r--r--block/genhd.c726
1 files changed, 726 insertions, 0 deletions
diff --git a/block/genhd.c b/block/genhd.c
new file mode 100644
index 0000000..54aec4a
--- /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);