diff options
Diffstat (limited to 'kernel/block/partition-generic.c')
| -rw-r--r-- | kernel/block/partition-generic.c | 571 |
1 files changed, 571 insertions, 0 deletions
diff --git a/kernel/block/partition-generic.c b/kernel/block/partition-generic.c new file mode 100644 index 000000000..0d9e5f97f --- /dev/null +++ b/kernel/block/partition-generic.c @@ -0,0 +1,571 @@ +/* + * 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); + free_part_stats(p); + free_part_info(p); + kfree(p); +} + +struct device_type part_type = { + .name = "partition", + .groups = part_attr_groups, + .release = part_release, +}; + +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 hd_struct *part) +{ + 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_put(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) + 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; + } + + /* 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); + + hd_ref_init(p); + 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_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) + 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); |