diff options
Diffstat (limited to 'drivers/block/genhd.c')
| -rw-r--r-- | drivers/block/genhd.c | 685 |
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); |