/* * 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; } struct blkdev_info { int index; struct blk_major_name *bd; }; /* * iterate over a list of blkdev_info structures. allows * the major_names array to be iterated over from outside this file * must be called with the block_subsys_sem held */ void *get_next_blkdev(void *dev) { struct blkdev_info *info; if (dev == NULL) { info = kmalloc(sizeof(*info), GFP_KERNEL); if (!info) goto out; info->index=0; info->bd = major_names[info->index]; if (info->bd) goto out; } else { info = dev; } while (info->index < ARRAY_SIZE(major_names)) { if (info->bd) info->bd = info->bd->next; if (info->bd) goto out; /* * No devices on this chain, move to the next */ info->index++; info->bd = (info->index < ARRAY_SIZE(major_names)) ? major_names[info->index] : NULL; if (info->bd) goto out; } out: return info; } void *acquire_blkdev_list(void) { down(&block_subsys_sem); return get_next_blkdev(NULL); } void release_blkdev_list(void *dev) { up(&block_subsys_sem); kfree(dev); } /* * Count the number of records in the blkdev_list. * must be called with the block_subsys_sem held */ int count_blkdev_list(void) { struct blk_major_name *n; int i, count; count = 0; for (i = 0; i < ARRAY_SIZE(major_names); i++) { for (n = major_names[i]; n; n = n->next) count++; } return count; } /* * extract the major and name values from a blkdev_info struct * passed in as a void to *dev. Must be called with * block_subsys_sem held */ int get_blkdev_info(void *dev, int *major, char **name) { struct blkdev_info *info = dev; if (info->bd == NULL) return 1; *major = info->bd->major; *name = info->bd->name; return 0; } 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_uevent(&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[READ]), disk_stat_read(disk, merges[READ]), (unsigned long long)disk_stat_read(disk, sectors[READ]), jiffies_to_msecs(disk_stat_read(disk, ticks[READ])), disk_stat_read(disk, ios[WRITE]), disk_stat_read(disk, merges[WRITE]), (unsigned long long)disk_stat_read(disk, sectors[WRITE]), jiffies_to_msecs(disk_stat_read(disk, ticks[WRITE])), 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_uevent_filter(struct kset *kset, struct kobject *kobj) { struct kobj_type *ktype = get_ktype(kobj); return ((ktype == &ktype_block) || (ktype == &ktype_part)); } static int block_uevent(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_uevent_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_uevent_var(envp, num_envp, &i, buffer, buffer_size, &length, "MINOR=%u", disk->first_minor + part->partno); } else return 0; add_uevent_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_uevent_var(envp, num_envp, &i, buffer, buffer_size, &length, "PHYSDEVPATH=%s", path); kfree(path); if (physdev->bus) add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &length, "PHYSDEVBUS=%s", physdev->bus->name); if (physdev->driver) add_uevent_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_uevent_ops block_uevent_ops = { .filter = block_uevent_filter, .uevent = block_uevent, }; /* declare block_subsys. */ static decl_subsys(block, &ktype_block, &block_uevent_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);