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https://github.com/torvalds/linux.git
synced 2024-12-05 10:32:35 +00:00
c2fccc1c9f
This reverts commit 8761a3dc1f
.
There are situations where the destruction path is called
with the bdev->bd_mutex already held, which then deadlocks in
loop_clr_fd(). The normal partition cleanup does a trylock()
on the mutex, but it'd be nice to have a more bullet proof
method in loop. So punt this more involved fix to the next
merge window, and just back out this buggy fix for now.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
572 lines
14 KiB
C
572 lines
14 KiB
C
/*
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* Code extracted from drivers/block/genhd.c
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* Copyright (C) 1991-1998 Linus Torvalds
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* Re-organised Feb 1998 Russell King
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*
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* We now have independent partition support from the
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* block drivers, which allows all the partition code to
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* be grouped in one location, and it to be mostly self
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* contained.
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*/
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/fs.h>
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#include <linux/slab.h>
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#include <linux/kmod.h>
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#include <linux/ctype.h>
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#include <linux/genhd.h>
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#include <linux/blktrace_api.h>
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#include "partitions/check.h"
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#ifdef CONFIG_BLK_DEV_MD
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extern void md_autodetect_dev(dev_t dev);
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#endif
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/*
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* disk_name() is used by partition check code and the genhd driver.
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* It formats the devicename of the indicated disk into
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* the supplied buffer (of size at least 32), and returns
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* a pointer to that same buffer (for convenience).
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*/
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char *disk_name(struct gendisk *hd, int partno, char *buf)
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{
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if (!partno)
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snprintf(buf, BDEVNAME_SIZE, "%s", hd->disk_name);
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else if (isdigit(hd->disk_name[strlen(hd->disk_name)-1]))
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snprintf(buf, BDEVNAME_SIZE, "%sp%d", hd->disk_name, partno);
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else
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snprintf(buf, BDEVNAME_SIZE, "%s%d", hd->disk_name, partno);
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return buf;
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}
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const char *bdevname(struct block_device *bdev, char *buf)
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{
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return disk_name(bdev->bd_disk, bdev->bd_part->partno, buf);
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}
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EXPORT_SYMBOL(bdevname);
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/*
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* There's very little reason to use this, you should really
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* have a struct block_device just about everywhere and use
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* bdevname() instead.
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*/
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const char *__bdevname(dev_t dev, char *buffer)
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{
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scnprintf(buffer, BDEVNAME_SIZE, "unknown-block(%u,%u)",
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MAJOR(dev), MINOR(dev));
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return buffer;
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}
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EXPORT_SYMBOL(__bdevname);
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static ssize_t part_partition_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct hd_struct *p = dev_to_part(dev);
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return sprintf(buf, "%d\n", p->partno);
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}
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static ssize_t part_start_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct hd_struct *p = dev_to_part(dev);
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return sprintf(buf, "%llu\n",(unsigned long long)p->start_sect);
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}
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ssize_t part_size_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct hd_struct *p = dev_to_part(dev);
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return sprintf(buf, "%llu\n",(unsigned long long)part_nr_sects_read(p));
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}
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static ssize_t part_ro_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct hd_struct *p = dev_to_part(dev);
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return sprintf(buf, "%d\n", p->policy ? 1 : 0);
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}
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static ssize_t part_alignment_offset_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct hd_struct *p = dev_to_part(dev);
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return sprintf(buf, "%llu\n", (unsigned long long)p->alignment_offset);
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}
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static ssize_t part_discard_alignment_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct hd_struct *p = dev_to_part(dev);
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return sprintf(buf, "%u\n", p->discard_alignment);
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}
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ssize_t part_stat_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct hd_struct *p = dev_to_part(dev);
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int cpu;
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cpu = part_stat_lock();
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part_round_stats(cpu, p);
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part_stat_unlock();
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return sprintf(buf,
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"%8lu %8lu %8llu %8u "
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"%8lu %8lu %8llu %8u "
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"%8u %8u %8u"
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"\n",
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part_stat_read(p, ios[READ]),
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part_stat_read(p, merges[READ]),
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(unsigned long long)part_stat_read(p, sectors[READ]),
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jiffies_to_msecs(part_stat_read(p, ticks[READ])),
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part_stat_read(p, ios[WRITE]),
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part_stat_read(p, merges[WRITE]),
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(unsigned long long)part_stat_read(p, sectors[WRITE]),
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jiffies_to_msecs(part_stat_read(p, ticks[WRITE])),
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part_in_flight(p),
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jiffies_to_msecs(part_stat_read(p, io_ticks)),
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jiffies_to_msecs(part_stat_read(p, time_in_queue)));
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}
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ssize_t part_inflight_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct hd_struct *p = dev_to_part(dev);
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return sprintf(buf, "%8u %8u\n", atomic_read(&p->in_flight[0]),
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atomic_read(&p->in_flight[1]));
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}
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#ifdef CONFIG_FAIL_MAKE_REQUEST
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ssize_t part_fail_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct hd_struct *p = dev_to_part(dev);
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return sprintf(buf, "%d\n", p->make_it_fail);
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}
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ssize_t part_fail_store(struct device *dev,
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struct device_attribute *attr,
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const char *buf, size_t count)
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{
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struct hd_struct *p = dev_to_part(dev);
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int i;
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if (count > 0 && sscanf(buf, "%d", &i) > 0)
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p->make_it_fail = (i == 0) ? 0 : 1;
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return count;
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}
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#endif
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static DEVICE_ATTR(partition, S_IRUGO, part_partition_show, NULL);
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static DEVICE_ATTR(start, S_IRUGO, part_start_show, NULL);
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static DEVICE_ATTR(size, S_IRUGO, part_size_show, NULL);
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static DEVICE_ATTR(ro, S_IRUGO, part_ro_show, NULL);
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static DEVICE_ATTR(alignment_offset, S_IRUGO, part_alignment_offset_show, NULL);
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static DEVICE_ATTR(discard_alignment, S_IRUGO, part_discard_alignment_show,
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NULL);
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static DEVICE_ATTR(stat, S_IRUGO, part_stat_show, NULL);
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static DEVICE_ATTR(inflight, S_IRUGO, part_inflight_show, NULL);
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#ifdef CONFIG_FAIL_MAKE_REQUEST
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static struct device_attribute dev_attr_fail =
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__ATTR(make-it-fail, S_IRUGO|S_IWUSR, part_fail_show, part_fail_store);
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#endif
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static struct attribute *part_attrs[] = {
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&dev_attr_partition.attr,
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&dev_attr_start.attr,
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&dev_attr_size.attr,
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&dev_attr_ro.attr,
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&dev_attr_alignment_offset.attr,
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&dev_attr_discard_alignment.attr,
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&dev_attr_stat.attr,
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&dev_attr_inflight.attr,
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#ifdef CONFIG_FAIL_MAKE_REQUEST
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&dev_attr_fail.attr,
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#endif
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NULL
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};
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static struct attribute_group part_attr_group = {
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.attrs = part_attrs,
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};
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static const struct attribute_group *part_attr_groups[] = {
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&part_attr_group,
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#ifdef CONFIG_BLK_DEV_IO_TRACE
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&blk_trace_attr_group,
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#endif
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NULL
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};
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static void part_release(struct device *dev)
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{
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struct hd_struct *p = dev_to_part(dev);
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free_part_stats(p);
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free_part_info(p);
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kfree(p);
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}
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struct device_type part_type = {
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.name = "partition",
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.groups = part_attr_groups,
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.release = part_release,
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};
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static void delete_partition_rcu_cb(struct rcu_head *head)
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{
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struct hd_struct *part = container_of(head, struct hd_struct, rcu_head);
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part->start_sect = 0;
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part->nr_sects = 0;
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part_stat_set_all(part, 0);
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put_device(part_to_dev(part));
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}
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void __delete_partition(struct hd_struct *part)
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{
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call_rcu(&part->rcu_head, delete_partition_rcu_cb);
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}
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void delete_partition(struct gendisk *disk, int partno)
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{
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struct disk_part_tbl *ptbl = disk->part_tbl;
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struct hd_struct *part;
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if (partno >= ptbl->len)
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return;
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part = ptbl->part[partno];
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if (!part)
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return;
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rcu_assign_pointer(ptbl->part[partno], NULL);
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rcu_assign_pointer(ptbl->last_lookup, NULL);
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kobject_put(part->holder_dir);
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device_del(part_to_dev(part));
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blk_free_devt(part_devt(part));
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hd_struct_put(part);
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}
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static ssize_t whole_disk_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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return 0;
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}
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static DEVICE_ATTR(whole_disk, S_IRUSR | S_IRGRP | S_IROTH,
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whole_disk_show, NULL);
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struct hd_struct *add_partition(struct gendisk *disk, int partno,
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sector_t start, sector_t len, int flags,
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struct partition_meta_info *info)
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{
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struct hd_struct *p;
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dev_t devt = MKDEV(0, 0);
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struct device *ddev = disk_to_dev(disk);
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struct device *pdev;
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struct disk_part_tbl *ptbl;
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const char *dname;
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int err;
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err = disk_expand_part_tbl(disk, partno);
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if (err)
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return ERR_PTR(err);
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ptbl = disk->part_tbl;
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if (ptbl->part[partno])
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return ERR_PTR(-EBUSY);
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p = kzalloc(sizeof(*p), GFP_KERNEL);
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if (!p)
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return ERR_PTR(-EBUSY);
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if (!init_part_stats(p)) {
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err = -ENOMEM;
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goto out_free;
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}
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seqcount_init(&p->nr_sects_seq);
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pdev = part_to_dev(p);
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p->start_sect = start;
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p->alignment_offset =
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queue_limit_alignment_offset(&disk->queue->limits, start);
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p->discard_alignment =
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queue_limit_discard_alignment(&disk->queue->limits, start);
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p->nr_sects = len;
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p->partno = partno;
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p->policy = get_disk_ro(disk);
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if (info) {
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struct partition_meta_info *pinfo = alloc_part_info(disk);
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if (!pinfo)
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goto out_free_stats;
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memcpy(pinfo, info, sizeof(*info));
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p->info = pinfo;
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}
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dname = dev_name(ddev);
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if (isdigit(dname[strlen(dname) - 1]))
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dev_set_name(pdev, "%sp%d", dname, partno);
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else
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dev_set_name(pdev, "%s%d", dname, partno);
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device_initialize(pdev);
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pdev->class = &block_class;
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pdev->type = &part_type;
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pdev->parent = ddev;
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err = blk_alloc_devt(p, &devt);
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if (err)
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goto out_free_info;
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pdev->devt = devt;
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/* delay uevent until 'holders' subdir is created */
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dev_set_uevent_suppress(pdev, 1);
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err = device_add(pdev);
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if (err)
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goto out_put;
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err = -ENOMEM;
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p->holder_dir = kobject_create_and_add("holders", &pdev->kobj);
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if (!p->holder_dir)
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goto out_del;
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dev_set_uevent_suppress(pdev, 0);
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if (flags & ADDPART_FLAG_WHOLEDISK) {
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err = device_create_file(pdev, &dev_attr_whole_disk);
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if (err)
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goto out_del;
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}
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/* everything is up and running, commence */
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rcu_assign_pointer(ptbl->part[partno], p);
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/* suppress uevent if the disk suppresses it */
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if (!dev_get_uevent_suppress(ddev))
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kobject_uevent(&pdev->kobj, KOBJ_ADD);
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hd_ref_init(p);
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return p;
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out_free_info:
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free_part_info(p);
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out_free_stats:
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free_part_stats(p);
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out_free:
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kfree(p);
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return ERR_PTR(err);
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out_del:
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kobject_put(p->holder_dir);
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device_del(pdev);
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out_put:
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put_device(pdev);
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blk_free_devt(devt);
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return ERR_PTR(err);
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}
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static bool disk_unlock_native_capacity(struct gendisk *disk)
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{
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const struct block_device_operations *bdops = disk->fops;
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if (bdops->unlock_native_capacity &&
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!(disk->flags & GENHD_FL_NATIVE_CAPACITY)) {
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printk(KERN_CONT "enabling native capacity\n");
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bdops->unlock_native_capacity(disk);
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disk->flags |= GENHD_FL_NATIVE_CAPACITY;
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return true;
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} else {
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printk(KERN_CONT "truncated\n");
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return false;
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}
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}
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static int drop_partitions(struct gendisk *disk, struct block_device *bdev)
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{
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struct disk_part_iter piter;
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struct hd_struct *part;
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int res;
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if (bdev->bd_part_count)
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return -EBUSY;
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res = invalidate_partition(disk, 0);
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if (res)
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return res;
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disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY);
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while ((part = disk_part_iter_next(&piter)))
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delete_partition(disk, part->partno);
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disk_part_iter_exit(&piter);
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return 0;
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}
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int rescan_partitions(struct gendisk *disk, struct block_device *bdev)
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{
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struct parsed_partitions *state = NULL;
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struct hd_struct *part;
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int p, highest, res;
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rescan:
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if (state && !IS_ERR(state)) {
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free_partitions(state);
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state = NULL;
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}
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res = drop_partitions(disk, bdev);
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if (res)
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return res;
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if (disk->fops->revalidate_disk)
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disk->fops->revalidate_disk(disk);
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check_disk_size_change(disk, bdev);
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bdev->bd_invalidated = 0;
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if (!get_capacity(disk) || !(state = check_partition(disk, bdev)))
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return 0;
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if (IS_ERR(state)) {
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/*
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* I/O error reading the partition table. If any
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* partition code tried to read beyond EOD, retry
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* after unlocking native capacity.
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*/
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if (PTR_ERR(state) == -ENOSPC) {
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printk(KERN_WARNING "%s: partition table beyond EOD, ",
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disk->disk_name);
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if (disk_unlock_native_capacity(disk))
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goto rescan;
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}
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return -EIO;
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}
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/*
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* If any partition code tried to read beyond EOD, try
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* unlocking native capacity even if partition table is
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* successfully read as we could be missing some partitions.
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*/
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if (state->access_beyond_eod) {
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printk(KERN_WARNING
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"%s: partition table partially beyond EOD, ",
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disk->disk_name);
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if (disk_unlock_native_capacity(disk))
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goto rescan;
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}
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/* tell userspace that the media / partition table may have changed */
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kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
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/* Detect the highest partition number and preallocate
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* disk->part_tbl. This is an optimization and not strictly
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* necessary.
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*/
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for (p = 1, highest = 0; p < state->limit; p++)
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if (state->parts[p].size)
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highest = p;
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disk_expand_part_tbl(disk, highest);
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/* add partitions */
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for (p = 1; p < state->limit; p++) {
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sector_t size, from;
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struct partition_meta_info *info = NULL;
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size = state->parts[p].size;
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if (!size)
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continue;
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from = state->parts[p].from;
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if (from >= get_capacity(disk)) {
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printk(KERN_WARNING
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"%s: p%d start %llu is beyond EOD, ",
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disk->disk_name, p, (unsigned long long) from);
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if (disk_unlock_native_capacity(disk))
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goto rescan;
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continue;
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}
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if (from + size > get_capacity(disk)) {
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printk(KERN_WARNING
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"%s: p%d size %llu extends beyond EOD, ",
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disk->disk_name, p, (unsigned long long) size);
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if (disk_unlock_native_capacity(disk)) {
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/* free state and restart */
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goto rescan;
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} else {
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/*
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* we can not ignore partitions of broken tables
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* 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);
|