606 lines
15 KiB
C
606 lines
15 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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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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const char *bio_devname(struct bio *bio, char *buf)
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{
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return disk_name(bio->bi_disk, bio->bi_partno, buf);
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}
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EXPORT_SYMBOL(bio_devname);
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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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struct request_queue *q = part_to_disk(p)->queue;
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unsigned int inflight;
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inflight = part_in_flight(q, p);
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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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"%8lu %8lu %8llu %8u "
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"%8lu %8u"
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"\n",
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part_stat_read(p, ios[STAT_READ]),
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part_stat_read(p, merges[STAT_READ]),
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(unsigned long long)part_stat_read(p, sectors[STAT_READ]),
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(unsigned int)part_stat_read_msecs(p, STAT_READ),
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part_stat_read(p, ios[STAT_WRITE]),
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part_stat_read(p, merges[STAT_WRITE]),
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(unsigned long long)part_stat_read(p, sectors[STAT_WRITE]),
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(unsigned int)part_stat_read_msecs(p, STAT_WRITE),
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inflight,
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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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part_stat_read(p, ios[STAT_DISCARD]),
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part_stat_read(p, merges[STAT_DISCARD]),
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(unsigned long long)part_stat_read(p, sectors[STAT_DISCARD]),
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(unsigned int)part_stat_read_msecs(p, STAT_DISCARD),
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part_stat_read(p, ios[STAT_FLUSH]),
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(unsigned int)part_stat_read_msecs(p, STAT_FLUSH));
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}
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ssize_t part_inflight_show(struct device *dev, struct device_attribute *attr,
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char *buf)
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{
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struct hd_struct *p = dev_to_part(dev);
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struct request_queue *q = part_to_disk(p)->queue;
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unsigned int inflight[2];
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part_in_flight_rw(q, p, inflight);
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return sprintf(buf, "%8u %8u\n", inflight[0], inflight[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, 0444, part_partition_show, NULL);
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static DEVICE_ATTR(start, 0444, part_start_show, NULL);
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static DEVICE_ATTR(size, 0444, part_size_show, NULL);
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static DEVICE_ATTR(ro, 0444, part_ro_show, NULL);
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static DEVICE_ATTR(alignment_offset, 0444, part_alignment_offset_show, NULL);
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static DEVICE_ATTR(discard_alignment, 0444, part_discard_alignment_show, NULL);
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static DEVICE_ATTR(stat, 0444, part_stat_show, NULL);
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static DEVICE_ATTR(inflight, 0444, 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, 0644, 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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blk_free_devt(dev->devt);
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hd_free_part(p);
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kfree(p);
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}
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static int part_uevent(struct device *dev, struct kobj_uevent_env *env)
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{
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struct hd_struct *part = dev_to_part(dev);
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add_uevent_var(env, "PARTN=%u", part->partno);
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if (part->info && part->info->volname[0])
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add_uevent_var(env, "PARTNAME=%s", part->info->volname);
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return 0;
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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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.uevent = part_uevent,
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};
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static void delete_partition_work_fn(struct work_struct *work)
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{
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struct hd_struct *part = container_of(to_rcu_work(work), struct hd_struct,
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rcu_work);
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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 percpu_ref *ref)
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{
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struct hd_struct *part = container_of(ref, struct hd_struct, ref);
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INIT_RCU_WORK(&part->rcu_work, delete_partition_work_fn);
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queue_rcu_work(system_wq, &part->rcu_work);
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}
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/*
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* Must be called either with bd_mutex held, before a disk can be opened or
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* after all disk users are gone.
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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 =
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rcu_dereference_protected(disk->part_tbl, 1);
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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 = rcu_dereference_protected(ptbl->part[partno], 1);
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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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/*
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* Remove gendisk pointer from idr so that it cannot be looked up
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* while RCU period before freeing gendisk is running to prevent
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* use-after-free issues. Note that the device number stays
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* "in-use" until we really free the gendisk.
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*/
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blk_invalidate_devt(part_devt(part));
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hd_struct_kill(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, 0444, whole_disk_show, NULL);
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/*
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* Must be called either with bd_mutex held, before a disk can be opened or
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* after all disk users are gone.
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*/
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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 = rcu_dereference_protected(disk->part_tbl, 1);
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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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err = -ENOMEM;
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goto out_free_stats;
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}
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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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err = hd_ref_init(p);
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if (err) {
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if (flags & ADDPART_FLAG_WHOLEDISK)
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goto out_remove_file;
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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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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_remove_file:
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device_remove_file(pdev, &dev_attr_whole_disk);
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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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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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int blk_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 (!disk_part_scan_enabled(disk))
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return 0;
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if (bdev->bd_part_count || bdev->bd_super)
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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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static bool blk_add_partition(struct gendisk *disk, struct block_device *bdev,
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struct parsed_partitions *state, int p)
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{
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sector_t size = state->parts[p].size;
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sector_t from = state->parts[p].from;
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struct hd_struct *part;
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if (!size)
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return true;
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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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return false;
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return true;
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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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return false;
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/*
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* We can not ignore partitions of broken tables created by for
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* example camera firmware, but we limit them to the end of the
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* disk to avoid creating invalid block devices.
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*/
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size = get_capacity(disk) - from;
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}
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part = add_partition(disk, p, from, size, state->parts[p].flags,
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&state->parts[p].info);
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if (IS_ERR(part)) {
|
|
printk(KERN_ERR " %s: p%d could not be added: %ld\n",
|
|
disk->disk_name, p, -PTR_ERR(part));
|
|
return true;
|
|
}
|
|
|
|
#ifdef CONFIG_BLK_DEV_MD
|
|
if (state->parts[p].flags & ADDPART_FLAG_RAID)
|
|
md_autodetect_dev(part_to_dev(part)->devt);
|
|
#endif
|
|
return true;
|
|
}
|
|
|
|
int blk_add_partitions(struct gendisk *disk, struct block_device *bdev)
|
|
{
|
|
struct parsed_partitions *state;
|
|
int ret = -EAGAIN, p, highest;
|
|
|
|
if (!disk_part_scan_enabled(disk))
|
|
return 0;
|
|
|
|
state = check_partition(disk, bdev);
|
|
if (!state)
|
|
return 0;
|
|
if (IS_ERR(state)) {
|
|
/*
|
|
* I/O error reading the partition table. If we tried to read
|
|
* beyond EOD, retry after unlocking the native capacity.
|
|
*/
|
|
if (PTR_ERR(state) == -ENOSPC) {
|
|
printk(KERN_WARNING "%s: partition table beyond EOD, ",
|
|
disk->disk_name);
|
|
if (disk_unlock_native_capacity(disk))
|
|
return -EAGAIN;
|
|
}
|
|
return -EIO;
|
|
}
|
|
|
|
/*
|
|
* Partitions are not supported on zoned block devices.
|
|
*/
|
|
if (bdev_is_zoned(bdev)) {
|
|
pr_warn("%s: ignoring partition table on zoned block device\n",
|
|
disk->disk_name);
|
|
ret = 0;
|
|
goto out_free_state;
|
|
}
|
|
|
|
/*
|
|
* If we read beyond EOD, try unlocking native capacity even if the
|
|
* partition table was 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 out_free_state;
|
|
}
|
|
|
|
/* 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);
|
|
|
|
for (p = 1; p < state->limit; p++)
|
|
if (!blk_add_partition(disk, bdev, state, p))
|
|
goto out_free_state;
|
|
|
|
ret = 0;
|
|
out_free_state:
|
|
free_partitions(state);
|
|
return ret;
|
|
}
|
|
|
|
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_SHIFT-9)), NULL);
|
|
if (!IS_ERR(page)) {
|
|
if (PageError(page))
|
|
goto fail;
|
|
p->v = page;
|
|
return (unsigned char *)page_address(page) + ((n & ((1 << (PAGE_SHIFT - 9)) - 1)) << 9);
|
|
fail:
|
|
put_page(page);
|
|
}
|
|
p->v = NULL;
|
|
return NULL;
|
|
}
|
|
|
|
EXPORT_SYMBOL(read_dev_sector);
|