| /* |
| * Code extracted from drivers/block/genhd.c |
| * Copyright (C) 1991-1998 Linus Torvalds |
| * Re-organised Feb 1998 Russell King |
| * |
| * We now have independent partition support from the |
| * block drivers, which allows all the partition code to |
| * be grouped in one location, and it to be mostly self |
| * contained. |
| */ |
| |
| #include <linux/init.h> |
| #include <linux/module.h> |
| #include <linux/fs.h> |
| #include <linux/slab.h> |
| #include <linux/kmod.h> |
| #include <linux/ctype.h> |
| #include <linux/genhd.h> |
| #include <linux/blktrace_api.h> |
| |
| #include "partitions/check.h" |
| |
| #ifdef CONFIG_BLK_DEV_MD |
| extern void md_autodetect_dev(dev_t dev); |
| #endif |
| |
| /* |
| * disk_name() is used by partition check code and the genhd driver. |
| * It formats the devicename of the indicated disk into |
| * the supplied buffer (of size at least 32), and returns |
| * a pointer to that same buffer (for convenience). |
| */ |
| |
| char *disk_name(struct gendisk *hd, int partno, char *buf) |
| { |
| if (!partno) |
| snprintf(buf, BDEVNAME_SIZE, "%s", hd->disk_name); |
| else if (isdigit(hd->disk_name[strlen(hd->disk_name)-1])) |
| snprintf(buf, BDEVNAME_SIZE, "%sp%d", hd->disk_name, partno); |
| else |
| snprintf(buf, BDEVNAME_SIZE, "%s%d", hd->disk_name, partno); |
| |
| return buf; |
| } |
| |
| const char *bdevname(struct block_device *bdev, char *buf) |
| { |
| return disk_name(bdev->bd_disk, bdev->bd_part->partno, buf); |
| } |
| |
| EXPORT_SYMBOL(bdevname); |
| |
| /* |
| * There's very little reason to use this, you should really |
| * have a struct block_device just about everywhere and use |
| * bdevname() instead. |
| */ |
| const char *__bdevname(dev_t dev, char *buffer) |
| { |
| scnprintf(buffer, BDEVNAME_SIZE, "unknown-block(%u,%u)", |
| MAJOR(dev), MINOR(dev)); |
| return buffer; |
| } |
| |
| EXPORT_SYMBOL(__bdevname); |
| |
| static ssize_t part_partition_show(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| struct hd_struct *p = dev_to_part(dev); |
| |
| return sprintf(buf, "%d\n", p->partno); |
| } |
| |
| static ssize_t part_start_show(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| struct hd_struct *p = dev_to_part(dev); |
| |
| return sprintf(buf, "%llu\n",(unsigned long long)p->start_sect); |
| } |
| |
| ssize_t part_size_show(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| struct hd_struct *p = dev_to_part(dev); |
| return sprintf(buf, "%llu\n",(unsigned long long)part_nr_sects_read(p)); |
| } |
| |
| static ssize_t part_ro_show(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| struct hd_struct *p = dev_to_part(dev); |
| return sprintf(buf, "%d\n", p->policy ? 1 : 0); |
| } |
| |
| static ssize_t part_alignment_offset_show(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| struct hd_struct *p = dev_to_part(dev); |
| return sprintf(buf, "%llu\n", (unsigned long long)p->alignment_offset); |
| } |
| |
| static ssize_t part_discard_alignment_show(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| struct hd_struct *p = dev_to_part(dev); |
| return sprintf(buf, "%u\n", p->discard_alignment); |
| } |
| |
| ssize_t part_stat_show(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| struct hd_struct *p = dev_to_part(dev); |
| int cpu; |
| |
| cpu = part_stat_lock(); |
| part_round_stats(cpu, p); |
| part_stat_unlock(); |
| return sprintf(buf, |
| "%8lu %8lu %8llu %8u " |
| "%8lu %8lu %8llu %8u " |
| "%8u %8u %8u" |
| "\n", |
| part_stat_read(p, ios[READ]), |
| part_stat_read(p, merges[READ]), |
| (unsigned long long)part_stat_read(p, sectors[READ]), |
| jiffies_to_msecs(part_stat_read(p, ticks[READ])), |
| part_stat_read(p, ios[WRITE]), |
| part_stat_read(p, merges[WRITE]), |
| (unsigned long long)part_stat_read(p, sectors[WRITE]), |
| jiffies_to_msecs(part_stat_read(p, ticks[WRITE])), |
| part_in_flight(p), |
| jiffies_to_msecs(part_stat_read(p, io_ticks)), |
| jiffies_to_msecs(part_stat_read(p, time_in_queue))); |
| } |
| |
| ssize_t part_inflight_show(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| struct hd_struct *p = dev_to_part(dev); |
| |
| return sprintf(buf, "%8u %8u\n", atomic_read(&p->in_flight[0]), |
| atomic_read(&p->in_flight[1])); |
| } |
| |
| #ifdef CONFIG_FAIL_MAKE_REQUEST |
| ssize_t part_fail_show(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| struct hd_struct *p = dev_to_part(dev); |
| |
| return sprintf(buf, "%d\n", p->make_it_fail); |
| } |
| |
| ssize_t part_fail_store(struct device *dev, |
| struct device_attribute *attr, |
| const char *buf, size_t count) |
| { |
| struct hd_struct *p = dev_to_part(dev); |
| int i; |
| |
| if (count > 0 && sscanf(buf, "%d", &i) > 0) |
| p->make_it_fail = (i == 0) ? 0 : 1; |
| |
| return count; |
| } |
| #endif |
| |
| static DEVICE_ATTR(partition, S_IRUGO, part_partition_show, NULL); |
| static DEVICE_ATTR(start, S_IRUGO, part_start_show, NULL); |
| static DEVICE_ATTR(size, S_IRUGO, part_size_show, NULL); |
| static DEVICE_ATTR(ro, S_IRUGO, part_ro_show, NULL); |
| static DEVICE_ATTR(alignment_offset, S_IRUGO, part_alignment_offset_show, NULL); |
| static DEVICE_ATTR(discard_alignment, S_IRUGO, part_discard_alignment_show, |
| NULL); |
| static DEVICE_ATTR(stat, S_IRUGO, part_stat_show, NULL); |
| static DEVICE_ATTR(inflight, S_IRUGO, part_inflight_show, NULL); |
| #ifdef CONFIG_FAIL_MAKE_REQUEST |
| static struct device_attribute dev_attr_fail = |
| __ATTR(make-it-fail, S_IRUGO|S_IWUSR, part_fail_show, part_fail_store); |
| #endif |
| |
| static struct attribute *part_attrs[] = { |
| &dev_attr_partition.attr, |
| &dev_attr_start.attr, |
| &dev_attr_size.attr, |
| &dev_attr_ro.attr, |
| &dev_attr_alignment_offset.attr, |
| &dev_attr_discard_alignment.attr, |
| &dev_attr_stat.attr, |
| &dev_attr_inflight.attr, |
| #ifdef CONFIG_FAIL_MAKE_REQUEST |
| &dev_attr_fail.attr, |
| #endif |
| NULL |
| }; |
| |
| static struct attribute_group part_attr_group = { |
| .attrs = part_attrs, |
| }; |
| |
| static const struct attribute_group *part_attr_groups[] = { |
| &part_attr_group, |
| #ifdef CONFIG_BLK_DEV_IO_TRACE |
| &blk_trace_attr_group, |
| #endif |
| NULL |
| }; |
| |
| static void part_release(struct device *dev) |
| { |
| struct hd_struct *p = dev_to_part(dev); |
| blk_free_devt(dev->devt); |
| hd_free_part(p); |
| kfree(p); |
| } |
| |
| static int part_uevent(struct device *dev, struct kobj_uevent_env *env) |
| { |
| struct hd_struct *part = dev_to_part(dev); |
| |
| add_uevent_var(env, "PARTN=%u", part->partno); |
| if (part->info && part->info->volname[0]) |
| add_uevent_var(env, "PARTNAME=%s", part->info->volname); |
| return 0; |
| } |
| |
| struct device_type part_type = { |
| .name = "partition", |
| .groups = part_attr_groups, |
| .release = part_release, |
| .uevent = part_uevent, |
| }; |
| |
| static void delete_partition_rcu_cb(struct rcu_head *head) |
| { |
| struct hd_struct *part = container_of(head, struct hd_struct, rcu_head); |
| |
| part->start_sect = 0; |
| part->nr_sects = 0; |
| part_stat_set_all(part, 0); |
| put_device(part_to_dev(part)); |
| } |
| |
| void __delete_partition(struct percpu_ref *ref) |
| { |
| struct hd_struct *part = container_of(ref, struct hd_struct, ref); |
| call_rcu(&part->rcu_head, delete_partition_rcu_cb); |
| } |
| |
| void delete_partition(struct gendisk *disk, int partno) |
| { |
| struct disk_part_tbl *ptbl = disk->part_tbl; |
| struct hd_struct *part; |
| |
| if (partno >= ptbl->len) |
| return; |
| |
| part = ptbl->part[partno]; |
| if (!part) |
| return; |
| |
| rcu_assign_pointer(ptbl->part[partno], NULL); |
| rcu_assign_pointer(ptbl->last_lookup, NULL); |
| kobject_put(part->holder_dir); |
| device_del(part_to_dev(part)); |
| |
| hd_struct_kill(part); |
| } |
| |
| static ssize_t whole_disk_show(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| return 0; |
| } |
| static DEVICE_ATTR(whole_disk, S_IRUSR | S_IRGRP | S_IROTH, |
| whole_disk_show, NULL); |
| |
| struct hd_struct *add_partition(struct gendisk *disk, int partno, |
| sector_t start, sector_t len, int flags, |
| struct partition_meta_info *info) |
| { |
| struct hd_struct *p; |
| dev_t devt = MKDEV(0, 0); |
| struct device *ddev = disk_to_dev(disk); |
| struct device *pdev; |
| struct disk_part_tbl *ptbl; |
| const char *dname; |
| int err; |
| |
| err = disk_expand_part_tbl(disk, partno); |
| if (err) |
| return ERR_PTR(err); |
| ptbl = disk->part_tbl; |
| |
| if (ptbl->part[partno]) |
| return ERR_PTR(-EBUSY); |
| |
| p = kzalloc(sizeof(*p), GFP_KERNEL); |
| if (!p) |
| return ERR_PTR(-EBUSY); |
| |
| if (!init_part_stats(p)) { |
| err = -ENOMEM; |
| goto out_free; |
| } |
| |
| seqcount_init(&p->nr_sects_seq); |
| pdev = part_to_dev(p); |
| |
| p->start_sect = start; |
| p->alignment_offset = |
| queue_limit_alignment_offset(&disk->queue->limits, start); |
| p->discard_alignment = |
| queue_limit_discard_alignment(&disk->queue->limits, start); |
| p->nr_sects = len; |
| p->partno = partno; |
| p->policy = get_disk_ro(disk); |
| |
| if (info) { |
| struct partition_meta_info *pinfo = alloc_part_info(disk); |
| if (!pinfo) { |
| err = -ENOMEM; |
| goto out_free_stats; |
| } |
| memcpy(pinfo, info, sizeof(*info)); |
| p->info = pinfo; |
| } |
| |
| dname = dev_name(ddev); |
| if (isdigit(dname[strlen(dname) - 1])) |
| dev_set_name(pdev, "%sp%d", dname, partno); |
| else |
| dev_set_name(pdev, "%s%d", dname, partno); |
| |
| device_initialize(pdev); |
| pdev->class = &block_class; |
| pdev->type = &part_type; |
| pdev->parent = ddev; |
| |
| err = blk_alloc_devt(p, &devt); |
| if (err) |
| goto out_free_info; |
| pdev->devt = devt; |
| |
| /* delay uevent until 'holders' subdir is created */ |
| dev_set_uevent_suppress(pdev, 1); |
| err = device_add(pdev); |
| if (err) |
| goto out_put; |
| |
| err = -ENOMEM; |
| p->holder_dir = kobject_create_and_add("holders", &pdev->kobj); |
| if (!p->holder_dir) |
| goto out_del; |
| |
| dev_set_uevent_suppress(pdev, 0); |
| if (flags & ADDPART_FLAG_WHOLEDISK) { |
| err = device_create_file(pdev, &dev_attr_whole_disk); |
| if (err) |
| goto out_del; |
| } |
| |
| err = hd_ref_init(p); |
| if (err) { |
| if (flags & ADDPART_FLAG_WHOLEDISK) |
| goto out_remove_file; |
| goto out_del; |
| } |
| |
| /* everything is up and running, commence */ |
| rcu_assign_pointer(ptbl->part[partno], p); |
| |
| /* suppress uevent if the disk suppresses it */ |
| if (!dev_get_uevent_suppress(ddev)) |
| kobject_uevent(&pdev->kobj, KOBJ_ADD); |
| return p; |
| |
| out_free_info: |
| free_part_info(p); |
| out_free_stats: |
| free_part_stats(p); |
| out_free: |
| kfree(p); |
| return ERR_PTR(err); |
| out_remove_file: |
| device_remove_file(pdev, &dev_attr_whole_disk); |
| out_del: |
| kobject_put(p->holder_dir); |
| device_del(pdev); |
| out_put: |
| put_device(pdev); |
| blk_free_devt(devt); |
| return ERR_PTR(err); |
| } |
| |
| static bool disk_unlock_native_capacity(struct gendisk *disk) |
| { |
| const struct block_device_operations *bdops = disk->fops; |
| |
| if (bdops->unlock_native_capacity && |
| !(disk->flags & GENHD_FL_NATIVE_CAPACITY)) { |
| printk(KERN_CONT "enabling native capacity\n"); |
| bdops->unlock_native_capacity(disk); |
| disk->flags |= GENHD_FL_NATIVE_CAPACITY; |
| return true; |
| } else { |
| printk(KERN_CONT "truncated\n"); |
| return false; |
| } |
| } |
| |
| static int drop_partitions(struct gendisk *disk, struct block_device *bdev) |
| { |
| struct disk_part_iter piter; |
| struct hd_struct *part; |
| int res; |
| |
| if (bdev->bd_part_count || bdev->bd_super) |
| return -EBUSY; |
| res = invalidate_partition(disk, 0); |
| if (res) |
| return res; |
| |
| disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY); |
| while ((part = disk_part_iter_next(&piter))) |
| delete_partition(disk, part->partno); |
| disk_part_iter_exit(&piter); |
| |
| return 0; |
| } |
| |
| int rescan_partitions(struct gendisk *disk, struct block_device *bdev) |
| { |
| struct parsed_partitions *state = NULL; |
| struct hd_struct *part; |
| int p, highest, res; |
| rescan: |
| if (state && !IS_ERR(state)) { |
| free_partitions(state); |
| state = NULL; |
| } |
| |
| res = drop_partitions(disk, bdev); |
| if (res) |
| return res; |
| |
| if (disk->fops->revalidate_disk) |
| disk->fops->revalidate_disk(disk); |
| check_disk_size_change(disk, bdev); |
| bdev->bd_invalidated = 0; |
| if (!get_capacity(disk) || !(state = check_partition(disk, bdev))) |
| return 0; |
| if (IS_ERR(state)) { |
| /* |
| * I/O error reading the partition table. If any |
| * partition code tried to read beyond EOD, retry |
| * after unlocking native capacity. |
| */ |
| if (PTR_ERR(state) == -ENOSPC) { |
| printk(KERN_WARNING "%s: partition table beyond EOD, ", |
| disk->disk_name); |
| if (disk_unlock_native_capacity(disk)) |
| goto rescan; |
| } |
| return -EIO; |
| } |
| /* |
| * If any partition code tried to read beyond EOD, try |
| * unlocking native capacity even if partition table is |
| * successfully read as we could be missing some partitions. |
| */ |
| if (state->access_beyond_eod) { |
| printk(KERN_WARNING |
| "%s: partition table partially beyond EOD, ", |
| disk->disk_name); |
| if (disk_unlock_native_capacity(disk)) |
| goto rescan; |
| } |
| |
| /* tell userspace that the media / partition table may have changed */ |
| kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE); |
| |
| /* Detect the highest partition number and preallocate |
| * disk->part_tbl. This is an optimization and not strictly |
| * necessary. |
| */ |
| for (p = 1, highest = 0; p < state->limit; p++) |
| if (state->parts[p].size) |
| highest = p; |
| |
| disk_expand_part_tbl(disk, highest); |
| |
| /* add partitions */ |
| for (p = 1; p < state->limit; p++) { |
| sector_t size, from; |
| struct partition_meta_info *info = NULL; |
| |
| size = state->parts[p].size; |
| if (!size) |
| continue; |
| |
| from = state->parts[p].from; |
| if (from >= get_capacity(disk)) { |
| printk(KERN_WARNING |
| "%s: p%d start %llu is beyond EOD, ", |
| disk->disk_name, p, (unsigned long long) from); |
| if (disk_unlock_native_capacity(disk)) |
| goto rescan; |
| continue; |
| } |
| |
| if (from + size > get_capacity(disk)) { |
| printk(KERN_WARNING |
| "%s: p%d size %llu extends beyond EOD, ", |
| disk->disk_name, p, (unsigned long long) size); |
| |
| if (disk_unlock_native_capacity(disk)) { |
| /* free state and restart */ |
| goto rescan; |
| } else { |
| /* |
| * we can not ignore partitions of broken tables |
| * created by for example camera firmware, but |
| * we limit them to the end of the disk to avoid |
| * creating invalid block devices |
| */ |
| size = get_capacity(disk) - from; |
| } |
| } |
| |
| if (state->parts[p].has_info) |
| info = &state->parts[p].info; |
| part = add_partition(disk, p, from, size, |
| state->parts[p].flags, |
| &state->parts[p].info); |
| if (IS_ERR(part)) { |
| printk(KERN_ERR " %s: p%d could not be added: %ld\n", |
| disk->disk_name, p, -PTR_ERR(part)); |
| continue; |
| } |
| #ifdef CONFIG_BLK_DEV_MD |
| if (state->parts[p].flags & ADDPART_FLAG_RAID) |
| md_autodetect_dev(part_to_dev(part)->devt); |
| #endif |
| } |
| free_partitions(state); |
| return 0; |
| } |
| |
| int invalidate_partitions(struct gendisk *disk, struct block_device *bdev) |
| { |
| int res; |
| |
| if (!bdev->bd_invalidated) |
| return 0; |
| |
| res = drop_partitions(disk, bdev); |
| if (res) |
| return res; |
| |
| set_capacity(disk, 0); |
| check_disk_size_change(disk, bdev); |
| bdev->bd_invalidated = 0; |
| /* tell userspace that the media / partition table may have changed */ |
| kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE); |
| |
| return 0; |
| } |
| |
| unsigned char *read_dev_sector(struct block_device *bdev, sector_t n, Sector *p) |
| { |
| struct address_space *mapping = bdev->bd_inode->i_mapping; |
| struct page *page; |
| |
| page = read_mapping_page(mapping, (pgoff_t)(n >> (PAGE_CACHE_SHIFT-9)), |
| NULL); |
| if (!IS_ERR(page)) { |
| if (PageError(page)) |
| goto fail; |
| p->v = page; |
| return (unsigned char *)page_address(page) + ((n & ((1 << (PAGE_CACHE_SHIFT - 9)) - 1)) << 9); |
| fail: |
| page_cache_release(page); |
| } |
| p->v = NULL; |
| return NULL; |
| } |
| |
| EXPORT_SYMBOL(read_dev_sector); |