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![Christoph Hellwig](/assets/img/avatar_default.png)
Just open code the xa_for_each in the remaining user. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20210406062303.811835-12-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
1865 lines
46 KiB
C
1865 lines
46 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* gendisk handling
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*
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* Portions Copyright (C) 2020 Christoph Hellwig
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*/
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#include <linux/module.h>
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#include <linux/ctype.h>
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#include <linux/fs.h>
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#include <linux/genhd.h>
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#include <linux/kdev_t.h>
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#include <linux/kernel.h>
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#include <linux/blkdev.h>
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#include <linux/backing-dev.h>
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#include <linux/init.h>
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#include <linux/spinlock.h>
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#include <linux/proc_fs.h>
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#include <linux/seq_file.h>
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#include <linux/slab.h>
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#include <linux/kmod.h>
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#include <linux/mutex.h>
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#include <linux/idr.h>
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#include <linux/log2.h>
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#include <linux/pm_runtime.h>
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#include <linux/badblocks.h>
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#include "blk.h"
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static struct kobject *block_depr;
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DECLARE_RWSEM(bdev_lookup_sem);
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/* for extended dynamic devt allocation, currently only one major is used */
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#define NR_EXT_DEVT (1 << MINORBITS)
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static DEFINE_IDA(ext_devt_ida);
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static void disk_check_events(struct disk_events *ev,
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unsigned int *clearing_ptr);
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static void disk_alloc_events(struct gendisk *disk);
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static void disk_add_events(struct gendisk *disk);
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static void disk_del_events(struct gendisk *disk);
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static void disk_release_events(struct gendisk *disk);
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void set_capacity(struct gendisk *disk, sector_t sectors)
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{
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struct block_device *bdev = disk->part0;
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spin_lock(&bdev->bd_size_lock);
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i_size_write(bdev->bd_inode, (loff_t)sectors << SECTOR_SHIFT);
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spin_unlock(&bdev->bd_size_lock);
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}
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EXPORT_SYMBOL(set_capacity);
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/*
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* Set disk capacity and notify if the size is not currently zero and will not
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* be set to zero. Returns true if a uevent was sent, otherwise false.
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*/
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bool set_capacity_and_notify(struct gendisk *disk, sector_t size)
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{
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sector_t capacity = get_capacity(disk);
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char *envp[] = { "RESIZE=1", NULL };
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set_capacity(disk, size);
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/*
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* Only print a message and send a uevent if the gendisk is user visible
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* and alive. This avoids spamming the log and udev when setting the
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* initial capacity during probing.
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*/
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if (size == capacity ||
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(disk->flags & (GENHD_FL_UP | GENHD_FL_HIDDEN)) != GENHD_FL_UP)
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return false;
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pr_info("%s: detected capacity change from %lld to %lld\n",
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disk->disk_name, capacity, size);
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/*
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* Historically we did not send a uevent for changes to/from an empty
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* device.
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*/
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if (!capacity || !size)
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return false;
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kobject_uevent_env(&disk_to_dev(disk)->kobj, KOBJ_CHANGE, envp);
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return true;
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}
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EXPORT_SYMBOL_GPL(set_capacity_and_notify);
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/*
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* Format the device name of the indicated disk into the supplied buffer and
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* return 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_partno, buf);
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}
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EXPORT_SYMBOL(bdevname);
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static void part_stat_read_all(struct block_device *part,
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struct disk_stats *stat)
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{
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int cpu;
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memset(stat, 0, sizeof(struct disk_stats));
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for_each_possible_cpu(cpu) {
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struct disk_stats *ptr = per_cpu_ptr(part->bd_stats, cpu);
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int group;
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for (group = 0; group < NR_STAT_GROUPS; group++) {
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stat->nsecs[group] += ptr->nsecs[group];
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stat->sectors[group] += ptr->sectors[group];
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stat->ios[group] += ptr->ios[group];
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stat->merges[group] += ptr->merges[group];
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}
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stat->io_ticks += ptr->io_ticks;
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}
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}
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static unsigned int part_in_flight(struct block_device *part)
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{
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unsigned int inflight = 0;
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int cpu;
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for_each_possible_cpu(cpu) {
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inflight += part_stat_local_read_cpu(part, in_flight[0], cpu) +
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part_stat_local_read_cpu(part, in_flight[1], cpu);
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}
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if ((int)inflight < 0)
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inflight = 0;
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return inflight;
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}
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static void part_in_flight_rw(struct block_device *part,
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unsigned int inflight[2])
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{
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int cpu;
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inflight[0] = 0;
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inflight[1] = 0;
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for_each_possible_cpu(cpu) {
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inflight[0] += part_stat_local_read_cpu(part, in_flight[0], cpu);
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inflight[1] += part_stat_local_read_cpu(part, in_flight[1], cpu);
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}
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if ((int)inflight[0] < 0)
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inflight[0] = 0;
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if ((int)inflight[1] < 0)
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inflight[1] = 0;
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}
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/*
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* Can be deleted altogether. Later.
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*
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*/
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#define BLKDEV_MAJOR_HASH_SIZE 255
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static struct blk_major_name {
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struct blk_major_name *next;
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int major;
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char name[16];
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void (*probe)(dev_t devt);
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} *major_names[BLKDEV_MAJOR_HASH_SIZE];
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static DEFINE_MUTEX(major_names_lock);
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/* index in the above - for now: assume no multimajor ranges */
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static inline int major_to_index(unsigned major)
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{
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return major % BLKDEV_MAJOR_HASH_SIZE;
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}
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#ifdef CONFIG_PROC_FS
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void blkdev_show(struct seq_file *seqf, off_t offset)
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{
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struct blk_major_name *dp;
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mutex_lock(&major_names_lock);
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for (dp = major_names[major_to_index(offset)]; dp; dp = dp->next)
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if (dp->major == offset)
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seq_printf(seqf, "%3d %s\n", dp->major, dp->name);
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mutex_unlock(&major_names_lock);
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}
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#endif /* CONFIG_PROC_FS */
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/**
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* __register_blkdev - register a new block device
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*
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* @major: the requested major device number [1..BLKDEV_MAJOR_MAX-1]. If
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* @major = 0, try to allocate any unused major number.
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* @name: the name of the new block device as a zero terminated string
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* @probe: allback that is called on access to any minor number of @major
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*
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* The @name must be unique within the system.
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*
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* The return value depends on the @major input parameter:
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*
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* - if a major device number was requested in range [1..BLKDEV_MAJOR_MAX-1]
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* then the function returns zero on success, or a negative error code
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* - if any unused major number was requested with @major = 0 parameter
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* then the return value is the allocated major number in range
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* [1..BLKDEV_MAJOR_MAX-1] or a negative error code otherwise
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*
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* See Documentation/admin-guide/devices.txt for the list of allocated
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* major numbers.
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*
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* Use register_blkdev instead for any new code.
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*/
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int __register_blkdev(unsigned int major, const char *name,
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void (*probe)(dev_t devt))
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{
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struct blk_major_name **n, *p;
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int index, ret = 0;
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mutex_lock(&major_names_lock);
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/* temporary */
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if (major == 0) {
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for (index = ARRAY_SIZE(major_names)-1; index > 0; index--) {
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if (major_names[index] == NULL)
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break;
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}
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if (index == 0) {
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printk("%s: failed to get major for %s\n",
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__func__, name);
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ret = -EBUSY;
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goto out;
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}
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major = index;
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ret = major;
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}
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if (major >= BLKDEV_MAJOR_MAX) {
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pr_err("%s: major requested (%u) is greater than the maximum (%u) for %s\n",
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__func__, major, BLKDEV_MAJOR_MAX-1, name);
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ret = -EINVAL;
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goto out;
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}
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p = kmalloc(sizeof(struct blk_major_name), GFP_KERNEL);
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if (p == NULL) {
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ret = -ENOMEM;
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goto out;
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}
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p->major = major;
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p->probe = probe;
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strlcpy(p->name, name, sizeof(p->name));
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p->next = NULL;
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index = major_to_index(major);
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for (n = &major_names[index]; *n; n = &(*n)->next) {
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if ((*n)->major == major)
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break;
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}
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if (!*n)
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*n = p;
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else
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ret = -EBUSY;
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if (ret < 0) {
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printk("register_blkdev: cannot get major %u for %s\n",
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major, name);
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kfree(p);
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}
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out:
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mutex_unlock(&major_names_lock);
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return ret;
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}
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EXPORT_SYMBOL(__register_blkdev);
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void unregister_blkdev(unsigned int major, const char *name)
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{
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struct blk_major_name **n;
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struct blk_major_name *p = NULL;
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int index = major_to_index(major);
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mutex_lock(&major_names_lock);
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for (n = &major_names[index]; *n; n = &(*n)->next)
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if ((*n)->major == major)
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break;
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if (!*n || strcmp((*n)->name, name)) {
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WARN_ON(1);
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} else {
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p = *n;
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*n = p->next;
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}
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mutex_unlock(&major_names_lock);
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kfree(p);
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}
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EXPORT_SYMBOL(unregister_blkdev);
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/**
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* blk_mangle_minor - scatter minor numbers apart
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* @minor: minor number to mangle
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*
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* Scatter consecutively allocated @minor number apart if MANGLE_DEVT
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* is enabled. Mangling twice gives the original value.
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*
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* RETURNS:
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* Mangled value.
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*
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* CONTEXT:
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* Don't care.
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*/
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static int blk_mangle_minor(int minor)
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{
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#ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT
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int i;
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for (i = 0; i < MINORBITS / 2; i++) {
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int low = minor & (1 << i);
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int high = minor & (1 << (MINORBITS - 1 - i));
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int distance = MINORBITS - 1 - 2 * i;
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minor ^= low | high; /* clear both bits */
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low <<= distance; /* swap the positions */
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high >>= distance;
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minor |= low | high; /* and set */
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}
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#endif
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return minor;
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}
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/**
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* blk_alloc_devt - allocate a dev_t for a block device
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* @bdev: block device to allocate dev_t for
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* @devt: out parameter for resulting dev_t
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*
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* Allocate a dev_t for block device.
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*
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* RETURNS:
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* 0 on success, allocated dev_t is returned in *@devt. -errno on
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* failure.
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*
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* CONTEXT:
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* Might sleep.
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*/
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int blk_alloc_devt(struct block_device *bdev, dev_t *devt)
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{
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struct gendisk *disk = bdev->bd_disk;
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int idx;
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/* in consecutive minor range? */
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if (bdev->bd_partno < disk->minors) {
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*devt = MKDEV(disk->major, disk->first_minor + bdev->bd_partno);
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return 0;
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}
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idx = ida_alloc_range(&ext_devt_ida, 0, NR_EXT_DEVT, GFP_KERNEL);
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if (idx < 0)
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return idx == -ENOSPC ? -EBUSY : idx;
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*devt = MKDEV(BLOCK_EXT_MAJOR, blk_mangle_minor(idx));
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return 0;
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}
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/**
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* blk_free_devt - free a dev_t
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* @devt: dev_t to free
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*
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* Free @devt which was allocated using blk_alloc_devt().
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*
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* CONTEXT:
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* Might sleep.
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*/
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void blk_free_devt(dev_t devt)
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{
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if (MAJOR(devt) == BLOCK_EXT_MAJOR)
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ida_free(&ext_devt_ida, blk_mangle_minor(MINOR(devt)));
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}
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static char *bdevt_str(dev_t devt, char *buf)
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{
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if (MAJOR(devt) <= 0xff && MINOR(devt) <= 0xff) {
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char tbuf[BDEVT_SIZE];
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snprintf(tbuf, BDEVT_SIZE, "%02x%02x", MAJOR(devt), MINOR(devt));
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snprintf(buf, BDEVT_SIZE, "%-9s", tbuf);
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} else
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snprintf(buf, BDEVT_SIZE, "%03x:%05x", MAJOR(devt), MINOR(devt));
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return buf;
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}
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void disk_uevent(struct gendisk *disk, enum kobject_action action)
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{
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struct block_device *part;
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unsigned long idx;
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rcu_read_lock();
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xa_for_each(&disk->part_tbl, idx, part) {
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if (bdev_is_partition(part) && !bdev_nr_sectors(part))
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continue;
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if (!bdgrab(part))
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continue;
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rcu_read_unlock();
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kobject_uevent(bdev_kobj(part), action);
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bdput(part);
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rcu_read_lock();
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}
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rcu_read_unlock();
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}
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EXPORT_SYMBOL_GPL(disk_uevent);
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static void disk_scan_partitions(struct gendisk *disk)
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{
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struct block_device *bdev;
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if (!get_capacity(disk) || !disk_part_scan_enabled(disk))
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return;
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set_bit(GD_NEED_PART_SCAN, &disk->state);
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bdev = blkdev_get_by_dev(disk_devt(disk), FMODE_READ, NULL);
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if (!IS_ERR(bdev))
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blkdev_put(bdev, FMODE_READ);
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}
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static void register_disk(struct device *parent, struct gendisk *disk,
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const struct attribute_group **groups)
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{
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struct device *ddev = disk_to_dev(disk);
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int err;
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ddev->parent = parent;
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dev_set_name(ddev, "%s", disk->disk_name);
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/* delay uevents, until we scanned partition table */
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dev_set_uevent_suppress(ddev, 1);
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if (groups) {
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WARN_ON(ddev->groups);
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ddev->groups = groups;
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}
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if (device_add(ddev))
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return;
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if (!sysfs_deprecated) {
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err = sysfs_create_link(block_depr, &ddev->kobj,
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kobject_name(&ddev->kobj));
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if (err) {
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device_del(ddev);
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return;
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}
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}
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|
|
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/*
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* avoid probable deadlock caused by allocating memory with
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* GFP_KERNEL in runtime_resume callback of its all ancestor
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* devices
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*/
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pm_runtime_set_memalloc_noio(ddev, true);
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disk->part0->bd_holder_dir =
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kobject_create_and_add("holders", &ddev->kobj);
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disk->slave_dir = kobject_create_and_add("slaves", &ddev->kobj);
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|
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if (disk->flags & GENHD_FL_HIDDEN)
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return;
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|
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disk_scan_partitions(disk);
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/* announce the disk and partitions after all partitions are created */
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dev_set_uevent_suppress(ddev, 0);
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disk_uevent(disk, KOBJ_ADD);
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|
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if (disk->queue->backing_dev_info->dev) {
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err = sysfs_create_link(&ddev->kobj,
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&disk->queue->backing_dev_info->dev->kobj,
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"bdi");
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WARN_ON(err);
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}
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}
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|
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/**
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* __device_add_disk - add disk information to kernel list
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* @parent: parent device for the disk
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* @disk: per-device partitioning information
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* @groups: Additional per-device sysfs groups
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* @register_queue: register the queue if set to true
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*
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* This function registers the partitioning information in @disk
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* with the kernel.
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*
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* FIXME: error handling
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*/
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static void __device_add_disk(struct device *parent, struct gendisk *disk,
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const struct attribute_group **groups,
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bool register_queue)
|
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{
|
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dev_t devt;
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int retval;
|
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|
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/*
|
|
* The disk queue should now be all set with enough information about
|
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* the device for the elevator code to pick an adequate default
|
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* elevator if one is needed, that is, for devices requesting queue
|
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* registration.
|
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*/
|
|
if (register_queue)
|
|
elevator_init_mq(disk->queue);
|
|
|
|
/* minors == 0 indicates to use ext devt from part0 and should
|
|
* be accompanied with EXT_DEVT flag. Make sure all
|
|
* parameters make sense.
|
|
*/
|
|
WARN_ON(disk->minors && !(disk->major || disk->first_minor));
|
|
WARN_ON(!disk->minors &&
|
|
!(disk->flags & (GENHD_FL_EXT_DEVT | GENHD_FL_HIDDEN)));
|
|
|
|
disk->flags |= GENHD_FL_UP;
|
|
|
|
retval = blk_alloc_devt(disk->part0, &devt);
|
|
if (retval) {
|
|
WARN_ON(1);
|
|
return;
|
|
}
|
|
disk->major = MAJOR(devt);
|
|
disk->first_minor = MINOR(devt);
|
|
|
|
disk_alloc_events(disk);
|
|
|
|
if (disk->flags & GENHD_FL_HIDDEN) {
|
|
/*
|
|
* Don't let hidden disks show up in /proc/partitions,
|
|
* and don't bother scanning for partitions either.
|
|
*/
|
|
disk->flags |= GENHD_FL_SUPPRESS_PARTITION_INFO;
|
|
disk->flags |= GENHD_FL_NO_PART_SCAN;
|
|
} else {
|
|
struct backing_dev_info *bdi = disk->queue->backing_dev_info;
|
|
struct device *dev = disk_to_dev(disk);
|
|
int ret;
|
|
|
|
/* Register BDI before referencing it from bdev */
|
|
dev->devt = devt;
|
|
ret = bdi_register(bdi, "%u:%u", MAJOR(devt), MINOR(devt));
|
|
WARN_ON(ret);
|
|
bdi_set_owner(bdi, dev);
|
|
bdev_add(disk->part0, devt);
|
|
}
|
|
register_disk(parent, disk, groups);
|
|
if (register_queue)
|
|
blk_register_queue(disk);
|
|
|
|
/*
|
|
* Take an extra ref on queue which will be put on disk_release()
|
|
* so that it sticks around as long as @disk is there.
|
|
*/
|
|
WARN_ON_ONCE(!blk_get_queue(disk->queue));
|
|
|
|
disk_add_events(disk);
|
|
blk_integrity_add(disk);
|
|
}
|
|
|
|
void device_add_disk(struct device *parent, struct gendisk *disk,
|
|
const struct attribute_group **groups)
|
|
|
|
{
|
|
__device_add_disk(parent, disk, groups, true);
|
|
}
|
|
EXPORT_SYMBOL(device_add_disk);
|
|
|
|
void device_add_disk_no_queue_reg(struct device *parent, struct gendisk *disk)
|
|
{
|
|
__device_add_disk(parent, disk, NULL, false);
|
|
}
|
|
EXPORT_SYMBOL(device_add_disk_no_queue_reg);
|
|
|
|
/**
|
|
* del_gendisk - remove the gendisk
|
|
* @disk: the struct gendisk to remove
|
|
*
|
|
* Removes the gendisk and all its associated resources. This deletes the
|
|
* partitions associated with the gendisk, and unregisters the associated
|
|
* request_queue.
|
|
*
|
|
* This is the counter to the respective __device_add_disk() call.
|
|
*
|
|
* The final removal of the struct gendisk happens when its refcount reaches 0
|
|
* with put_disk(), which should be called after del_gendisk(), if
|
|
* __device_add_disk() was used.
|
|
*
|
|
* Drivers exist which depend on the release of the gendisk to be synchronous,
|
|
* it should not be deferred.
|
|
*
|
|
* Context: can sleep
|
|
*/
|
|
void del_gendisk(struct gendisk *disk)
|
|
{
|
|
might_sleep();
|
|
|
|
if (WARN_ON_ONCE(!disk->queue))
|
|
return;
|
|
|
|
blk_integrity_del(disk);
|
|
disk_del_events(disk);
|
|
|
|
/*
|
|
* Block lookups of the disk until all bdevs are unhashed and the
|
|
* disk is marked as dead (GENHD_FL_UP cleared).
|
|
*/
|
|
down_write(&bdev_lookup_sem);
|
|
|
|
mutex_lock(&disk->part0->bd_mutex);
|
|
blk_drop_partitions(disk);
|
|
mutex_unlock(&disk->part0->bd_mutex);
|
|
|
|
fsync_bdev(disk->part0);
|
|
__invalidate_device(disk->part0, true);
|
|
|
|
/*
|
|
* Unhash the bdev inode for this device so that it can't be looked
|
|
* up any more even if openers still hold references to it.
|
|
*/
|
|
remove_inode_hash(disk->part0->bd_inode);
|
|
|
|
set_capacity(disk, 0);
|
|
disk->flags &= ~GENHD_FL_UP;
|
|
up_write(&bdev_lookup_sem);
|
|
|
|
if (!(disk->flags & GENHD_FL_HIDDEN)) {
|
|
sysfs_remove_link(&disk_to_dev(disk)->kobj, "bdi");
|
|
|
|
/*
|
|
* Unregister bdi before releasing device numbers (as they can
|
|
* get reused and we'd get clashes in sysfs).
|
|
*/
|
|
bdi_unregister(disk->queue->backing_dev_info);
|
|
}
|
|
|
|
blk_unregister_queue(disk);
|
|
|
|
kobject_put(disk->part0->bd_holder_dir);
|
|
kobject_put(disk->slave_dir);
|
|
|
|
part_stat_set_all(disk->part0, 0);
|
|
disk->part0->bd_stamp = 0;
|
|
if (!sysfs_deprecated)
|
|
sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk)));
|
|
pm_runtime_set_memalloc_noio(disk_to_dev(disk), false);
|
|
device_del(disk_to_dev(disk));
|
|
}
|
|
EXPORT_SYMBOL(del_gendisk);
|
|
|
|
/* sysfs access to bad-blocks list. */
|
|
static ssize_t disk_badblocks_show(struct device *dev,
|
|
struct device_attribute *attr,
|
|
char *page)
|
|
{
|
|
struct gendisk *disk = dev_to_disk(dev);
|
|
|
|
if (!disk->bb)
|
|
return sprintf(page, "\n");
|
|
|
|
return badblocks_show(disk->bb, page, 0);
|
|
}
|
|
|
|
static ssize_t disk_badblocks_store(struct device *dev,
|
|
struct device_attribute *attr,
|
|
const char *page, size_t len)
|
|
{
|
|
struct gendisk *disk = dev_to_disk(dev);
|
|
|
|
if (!disk->bb)
|
|
return -ENXIO;
|
|
|
|
return badblocks_store(disk->bb, page, len, 0);
|
|
}
|
|
|
|
void blk_request_module(dev_t devt)
|
|
{
|
|
unsigned int major = MAJOR(devt);
|
|
struct blk_major_name **n;
|
|
|
|
mutex_lock(&major_names_lock);
|
|
for (n = &major_names[major_to_index(major)]; *n; n = &(*n)->next) {
|
|
if ((*n)->major == major && (*n)->probe) {
|
|
(*n)->probe(devt);
|
|
mutex_unlock(&major_names_lock);
|
|
return;
|
|
}
|
|
}
|
|
mutex_unlock(&major_names_lock);
|
|
|
|
if (request_module("block-major-%d-%d", MAJOR(devt), MINOR(devt)) > 0)
|
|
/* Make old-style 2.4 aliases work */
|
|
request_module("block-major-%d", MAJOR(devt));
|
|
}
|
|
|
|
/**
|
|
* bdget_disk - do bdget() by gendisk and partition number
|
|
* @disk: gendisk of interest
|
|
* @partno: partition number
|
|
*
|
|
* Find partition @partno from @disk, do bdget() on it.
|
|
*
|
|
* CONTEXT:
|
|
* Don't care.
|
|
*
|
|
* RETURNS:
|
|
* Resulting block_device on success, NULL on failure.
|
|
*/
|
|
struct block_device *bdget_disk(struct gendisk *disk, int partno)
|
|
{
|
|
struct block_device *bdev = NULL;
|
|
|
|
rcu_read_lock();
|
|
bdev = xa_load(&disk->part_tbl, partno);
|
|
if (bdev && !bdgrab(bdev))
|
|
bdev = NULL;
|
|
rcu_read_unlock();
|
|
|
|
return bdev;
|
|
}
|
|
|
|
/*
|
|
* print a full list of all partitions - intended for places where the root
|
|
* filesystem can't be mounted and thus to give the victim some idea of what
|
|
* went wrong
|
|
*/
|
|
void __init printk_all_partitions(void)
|
|
{
|
|
struct class_dev_iter iter;
|
|
struct device *dev;
|
|
|
|
class_dev_iter_init(&iter, &block_class, NULL, &disk_type);
|
|
while ((dev = class_dev_iter_next(&iter))) {
|
|
struct gendisk *disk = dev_to_disk(dev);
|
|
struct block_device *part;
|
|
char name_buf[BDEVNAME_SIZE];
|
|
char devt_buf[BDEVT_SIZE];
|
|
unsigned long idx;
|
|
|
|
/*
|
|
* Don't show empty devices or things that have been
|
|
* suppressed
|
|
*/
|
|
if (get_capacity(disk) == 0 ||
|
|
(disk->flags & GENHD_FL_SUPPRESS_PARTITION_INFO))
|
|
continue;
|
|
|
|
/*
|
|
* Note, unlike /proc/partitions, I am showing the numbers in
|
|
* hex - the same format as the root= option takes.
|
|
*/
|
|
rcu_read_lock();
|
|
xa_for_each(&disk->part_tbl, idx, part) {
|
|
if (!bdev_nr_sectors(part))
|
|
continue;
|
|
printk("%s%s %10llu %s %s",
|
|
bdev_is_partition(part) ? " " : "",
|
|
bdevt_str(part->bd_dev, devt_buf),
|
|
bdev_nr_sectors(part) >> 1,
|
|
disk_name(disk, part->bd_partno, name_buf),
|
|
part->bd_meta_info ?
|
|
part->bd_meta_info->uuid : "");
|
|
if (bdev_is_partition(part))
|
|
printk("\n");
|
|
else if (dev->parent && dev->parent->driver)
|
|
printk(" driver: %s\n",
|
|
dev->parent->driver->name);
|
|
else
|
|
printk(" (driver?)\n");
|
|
}
|
|
rcu_read_unlock();
|
|
}
|
|
class_dev_iter_exit(&iter);
|
|
}
|
|
|
|
#ifdef CONFIG_PROC_FS
|
|
/* iterator */
|
|
static void *disk_seqf_start(struct seq_file *seqf, loff_t *pos)
|
|
{
|
|
loff_t skip = *pos;
|
|
struct class_dev_iter *iter;
|
|
struct device *dev;
|
|
|
|
iter = kmalloc(sizeof(*iter), GFP_KERNEL);
|
|
if (!iter)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
seqf->private = iter;
|
|
class_dev_iter_init(iter, &block_class, NULL, &disk_type);
|
|
do {
|
|
dev = class_dev_iter_next(iter);
|
|
if (!dev)
|
|
return NULL;
|
|
} while (skip--);
|
|
|
|
return dev_to_disk(dev);
|
|
}
|
|
|
|
static void *disk_seqf_next(struct seq_file *seqf, void *v, loff_t *pos)
|
|
{
|
|
struct device *dev;
|
|
|
|
(*pos)++;
|
|
dev = class_dev_iter_next(seqf->private);
|
|
if (dev)
|
|
return dev_to_disk(dev);
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static void disk_seqf_stop(struct seq_file *seqf, void *v)
|
|
{
|
|
struct class_dev_iter *iter = seqf->private;
|
|
|
|
/* stop is called even after start failed :-( */
|
|
if (iter) {
|
|
class_dev_iter_exit(iter);
|
|
kfree(iter);
|
|
seqf->private = NULL;
|
|
}
|
|
}
|
|
|
|
static void *show_partition_start(struct seq_file *seqf, loff_t *pos)
|
|
{
|
|
void *p;
|
|
|
|
p = disk_seqf_start(seqf, pos);
|
|
if (!IS_ERR_OR_NULL(p) && !*pos)
|
|
seq_puts(seqf, "major minor #blocks name\n\n");
|
|
return p;
|
|
}
|
|
|
|
static int show_partition(struct seq_file *seqf, void *v)
|
|
{
|
|
struct gendisk *sgp = v;
|
|
struct block_device *part;
|
|
unsigned long idx;
|
|
char buf[BDEVNAME_SIZE];
|
|
|
|
/* Don't show non-partitionable removeable devices or empty devices */
|
|
if (!get_capacity(sgp) || (!disk_max_parts(sgp) &&
|
|
(sgp->flags & GENHD_FL_REMOVABLE)))
|
|
return 0;
|
|
if (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO)
|
|
return 0;
|
|
|
|
rcu_read_lock();
|
|
xa_for_each(&sgp->part_tbl, idx, part) {
|
|
if (!bdev_nr_sectors(part))
|
|
continue;
|
|
seq_printf(seqf, "%4d %7d %10llu %s\n",
|
|
MAJOR(part->bd_dev), MINOR(part->bd_dev),
|
|
bdev_nr_sectors(part) >> 1,
|
|
disk_name(sgp, part->bd_partno, buf));
|
|
}
|
|
rcu_read_unlock();
|
|
return 0;
|
|
}
|
|
|
|
static const struct seq_operations partitions_op = {
|
|
.start = show_partition_start,
|
|
.next = disk_seqf_next,
|
|
.stop = disk_seqf_stop,
|
|
.show = show_partition
|
|
};
|
|
#endif
|
|
|
|
static int __init genhd_device_init(void)
|
|
{
|
|
int error;
|
|
|
|
block_class.dev_kobj = sysfs_dev_block_kobj;
|
|
error = class_register(&block_class);
|
|
if (unlikely(error))
|
|
return error;
|
|
blk_dev_init();
|
|
|
|
register_blkdev(BLOCK_EXT_MAJOR, "blkext");
|
|
|
|
/* create top-level block dir */
|
|
if (!sysfs_deprecated)
|
|
block_depr = kobject_create_and_add("block", NULL);
|
|
return 0;
|
|
}
|
|
|
|
subsys_initcall(genhd_device_init);
|
|
|
|
static ssize_t disk_range_show(struct device *dev,
|
|
struct device_attribute *attr, char *buf)
|
|
{
|
|
struct gendisk *disk = dev_to_disk(dev);
|
|
|
|
return sprintf(buf, "%d\n", disk->minors);
|
|
}
|
|
|
|
static ssize_t disk_ext_range_show(struct device *dev,
|
|
struct device_attribute *attr, char *buf)
|
|
{
|
|
struct gendisk *disk = dev_to_disk(dev);
|
|
|
|
return sprintf(buf, "%d\n", disk_max_parts(disk));
|
|
}
|
|
|
|
static ssize_t disk_removable_show(struct device *dev,
|
|
struct device_attribute *attr, char *buf)
|
|
{
|
|
struct gendisk *disk = dev_to_disk(dev);
|
|
|
|
return sprintf(buf, "%d\n",
|
|
(disk->flags & GENHD_FL_REMOVABLE ? 1 : 0));
|
|
}
|
|
|
|
static ssize_t disk_hidden_show(struct device *dev,
|
|
struct device_attribute *attr, char *buf)
|
|
{
|
|
struct gendisk *disk = dev_to_disk(dev);
|
|
|
|
return sprintf(buf, "%d\n",
|
|
(disk->flags & GENHD_FL_HIDDEN ? 1 : 0));
|
|
}
|
|
|
|
static ssize_t disk_ro_show(struct device *dev,
|
|
struct device_attribute *attr, char *buf)
|
|
{
|
|
struct gendisk *disk = dev_to_disk(dev);
|
|
|
|
return sprintf(buf, "%d\n", get_disk_ro(disk) ? 1 : 0);
|
|
}
|
|
|
|
ssize_t part_size_show(struct device *dev,
|
|
struct device_attribute *attr, char *buf)
|
|
{
|
|
return sprintf(buf, "%llu\n", bdev_nr_sectors(dev_to_bdev(dev)));
|
|
}
|
|
|
|
ssize_t part_stat_show(struct device *dev,
|
|
struct device_attribute *attr, char *buf)
|
|
{
|
|
struct block_device *bdev = dev_to_bdev(dev);
|
|
struct request_queue *q = bdev->bd_disk->queue;
|
|
struct disk_stats stat;
|
|
unsigned int inflight;
|
|
|
|
part_stat_read_all(bdev, &stat);
|
|
if (queue_is_mq(q))
|
|
inflight = blk_mq_in_flight(q, bdev);
|
|
else
|
|
inflight = part_in_flight(bdev);
|
|
|
|
return sprintf(buf,
|
|
"%8lu %8lu %8llu %8u "
|
|
"%8lu %8lu %8llu %8u "
|
|
"%8u %8u %8u "
|
|
"%8lu %8lu %8llu %8u "
|
|
"%8lu %8u"
|
|
"\n",
|
|
stat.ios[STAT_READ],
|
|
stat.merges[STAT_READ],
|
|
(unsigned long long)stat.sectors[STAT_READ],
|
|
(unsigned int)div_u64(stat.nsecs[STAT_READ], NSEC_PER_MSEC),
|
|
stat.ios[STAT_WRITE],
|
|
stat.merges[STAT_WRITE],
|
|
(unsigned long long)stat.sectors[STAT_WRITE],
|
|
(unsigned int)div_u64(stat.nsecs[STAT_WRITE], NSEC_PER_MSEC),
|
|
inflight,
|
|
jiffies_to_msecs(stat.io_ticks),
|
|
(unsigned int)div_u64(stat.nsecs[STAT_READ] +
|
|
stat.nsecs[STAT_WRITE] +
|
|
stat.nsecs[STAT_DISCARD] +
|
|
stat.nsecs[STAT_FLUSH],
|
|
NSEC_PER_MSEC),
|
|
stat.ios[STAT_DISCARD],
|
|
stat.merges[STAT_DISCARD],
|
|
(unsigned long long)stat.sectors[STAT_DISCARD],
|
|
(unsigned int)div_u64(stat.nsecs[STAT_DISCARD], NSEC_PER_MSEC),
|
|
stat.ios[STAT_FLUSH],
|
|
(unsigned int)div_u64(stat.nsecs[STAT_FLUSH], NSEC_PER_MSEC));
|
|
}
|
|
|
|
ssize_t part_inflight_show(struct device *dev, struct device_attribute *attr,
|
|
char *buf)
|
|
{
|
|
struct block_device *bdev = dev_to_bdev(dev);
|
|
struct request_queue *q = bdev->bd_disk->queue;
|
|
unsigned int inflight[2];
|
|
|
|
if (queue_is_mq(q))
|
|
blk_mq_in_flight_rw(q, bdev, inflight);
|
|
else
|
|
part_in_flight_rw(bdev, inflight);
|
|
|
|
return sprintf(buf, "%8u %8u\n", inflight[0], inflight[1]);
|
|
}
|
|
|
|
static ssize_t disk_capability_show(struct device *dev,
|
|
struct device_attribute *attr, char *buf)
|
|
{
|
|
struct gendisk *disk = dev_to_disk(dev);
|
|
|
|
return sprintf(buf, "%x\n", disk->flags);
|
|
}
|
|
|
|
static ssize_t disk_alignment_offset_show(struct device *dev,
|
|
struct device_attribute *attr,
|
|
char *buf)
|
|
{
|
|
struct gendisk *disk = dev_to_disk(dev);
|
|
|
|
return sprintf(buf, "%d\n", queue_alignment_offset(disk->queue));
|
|
}
|
|
|
|
static ssize_t disk_discard_alignment_show(struct device *dev,
|
|
struct device_attribute *attr,
|
|
char *buf)
|
|
{
|
|
struct gendisk *disk = dev_to_disk(dev);
|
|
|
|
return sprintf(buf, "%d\n", queue_discard_alignment(disk->queue));
|
|
}
|
|
|
|
static DEVICE_ATTR(range, 0444, disk_range_show, NULL);
|
|
static DEVICE_ATTR(ext_range, 0444, disk_ext_range_show, NULL);
|
|
static DEVICE_ATTR(removable, 0444, disk_removable_show, NULL);
|
|
static DEVICE_ATTR(hidden, 0444, disk_hidden_show, NULL);
|
|
static DEVICE_ATTR(ro, 0444, disk_ro_show, NULL);
|
|
static DEVICE_ATTR(size, 0444, part_size_show, NULL);
|
|
static DEVICE_ATTR(alignment_offset, 0444, disk_alignment_offset_show, NULL);
|
|
static DEVICE_ATTR(discard_alignment, 0444, disk_discard_alignment_show, NULL);
|
|
static DEVICE_ATTR(capability, 0444, disk_capability_show, NULL);
|
|
static DEVICE_ATTR(stat, 0444, part_stat_show, NULL);
|
|
static DEVICE_ATTR(inflight, 0444, part_inflight_show, NULL);
|
|
static DEVICE_ATTR(badblocks, 0644, disk_badblocks_show, disk_badblocks_store);
|
|
|
|
#ifdef CONFIG_FAIL_MAKE_REQUEST
|
|
ssize_t part_fail_show(struct device *dev,
|
|
struct device_attribute *attr, char *buf)
|
|
{
|
|
return sprintf(buf, "%d\n", dev_to_bdev(dev)->bd_make_it_fail);
|
|
}
|
|
|
|
ssize_t part_fail_store(struct device *dev,
|
|
struct device_attribute *attr,
|
|
const char *buf, size_t count)
|
|
{
|
|
int i;
|
|
|
|
if (count > 0 && sscanf(buf, "%d", &i) > 0)
|
|
dev_to_bdev(dev)->bd_make_it_fail = i;
|
|
|
|
return count;
|
|
}
|
|
|
|
static struct device_attribute dev_attr_fail =
|
|
__ATTR(make-it-fail, 0644, part_fail_show, part_fail_store);
|
|
#endif /* CONFIG_FAIL_MAKE_REQUEST */
|
|
|
|
#ifdef CONFIG_FAIL_IO_TIMEOUT
|
|
static struct device_attribute dev_attr_fail_timeout =
|
|
__ATTR(io-timeout-fail, 0644, part_timeout_show, part_timeout_store);
|
|
#endif
|
|
|
|
static struct attribute *disk_attrs[] = {
|
|
&dev_attr_range.attr,
|
|
&dev_attr_ext_range.attr,
|
|
&dev_attr_removable.attr,
|
|
&dev_attr_hidden.attr,
|
|
&dev_attr_ro.attr,
|
|
&dev_attr_size.attr,
|
|
&dev_attr_alignment_offset.attr,
|
|
&dev_attr_discard_alignment.attr,
|
|
&dev_attr_capability.attr,
|
|
&dev_attr_stat.attr,
|
|
&dev_attr_inflight.attr,
|
|
&dev_attr_badblocks.attr,
|
|
#ifdef CONFIG_FAIL_MAKE_REQUEST
|
|
&dev_attr_fail.attr,
|
|
#endif
|
|
#ifdef CONFIG_FAIL_IO_TIMEOUT
|
|
&dev_attr_fail_timeout.attr,
|
|
#endif
|
|
NULL
|
|
};
|
|
|
|
static umode_t disk_visible(struct kobject *kobj, struct attribute *a, int n)
|
|
{
|
|
struct device *dev = container_of(kobj, typeof(*dev), kobj);
|
|
struct gendisk *disk = dev_to_disk(dev);
|
|
|
|
if (a == &dev_attr_badblocks.attr && !disk->bb)
|
|
return 0;
|
|
return a->mode;
|
|
}
|
|
|
|
static struct attribute_group disk_attr_group = {
|
|
.attrs = disk_attrs,
|
|
.is_visible = disk_visible,
|
|
};
|
|
|
|
static const struct attribute_group *disk_attr_groups[] = {
|
|
&disk_attr_group,
|
|
NULL
|
|
};
|
|
|
|
/**
|
|
* disk_release - releases all allocated resources of the gendisk
|
|
* @dev: the device representing this disk
|
|
*
|
|
* This function releases all allocated resources of the gendisk.
|
|
*
|
|
* Drivers which used __device_add_disk() have a gendisk with a request_queue
|
|
* assigned. Since the request_queue sits on top of the gendisk for these
|
|
* drivers we also call blk_put_queue() for them, and we expect the
|
|
* request_queue refcount to reach 0 at this point, and so the request_queue
|
|
* will also be freed prior to the disk.
|
|
*
|
|
* Context: can sleep
|
|
*/
|
|
static void disk_release(struct device *dev)
|
|
{
|
|
struct gendisk *disk = dev_to_disk(dev);
|
|
|
|
might_sleep();
|
|
|
|
blk_free_devt(dev->devt);
|
|
disk_release_events(disk);
|
|
kfree(disk->random);
|
|
xa_destroy(&disk->part_tbl);
|
|
bdput(disk->part0);
|
|
if (disk->queue)
|
|
blk_put_queue(disk->queue);
|
|
kfree(disk);
|
|
}
|
|
struct class block_class = {
|
|
.name = "block",
|
|
};
|
|
|
|
static char *block_devnode(struct device *dev, umode_t *mode,
|
|
kuid_t *uid, kgid_t *gid)
|
|
{
|
|
struct gendisk *disk = dev_to_disk(dev);
|
|
|
|
if (disk->fops->devnode)
|
|
return disk->fops->devnode(disk, mode);
|
|
return NULL;
|
|
}
|
|
|
|
const struct device_type disk_type = {
|
|
.name = "disk",
|
|
.groups = disk_attr_groups,
|
|
.release = disk_release,
|
|
.devnode = block_devnode,
|
|
};
|
|
|
|
#ifdef CONFIG_PROC_FS
|
|
/*
|
|
* aggregate disk stat collector. Uses the same stats that the sysfs
|
|
* entries do, above, but makes them available through one seq_file.
|
|
*
|
|
* The output looks suspiciously like /proc/partitions with a bunch of
|
|
* extra fields.
|
|
*/
|
|
static int diskstats_show(struct seq_file *seqf, void *v)
|
|
{
|
|
struct gendisk *gp = v;
|
|
struct block_device *hd;
|
|
char buf[BDEVNAME_SIZE];
|
|
unsigned int inflight;
|
|
struct disk_stats stat;
|
|
unsigned long idx;
|
|
|
|
/*
|
|
if (&disk_to_dev(gp)->kobj.entry == block_class.devices.next)
|
|
seq_puts(seqf, "major minor name"
|
|
" rio rmerge rsect ruse wio wmerge "
|
|
"wsect wuse running use aveq"
|
|
"\n\n");
|
|
*/
|
|
|
|
rcu_read_lock();
|
|
xa_for_each(&gp->part_tbl, idx, hd) {
|
|
if (bdev_is_partition(hd) && !bdev_nr_sectors(hd))
|
|
continue;
|
|
part_stat_read_all(hd, &stat);
|
|
if (queue_is_mq(gp->queue))
|
|
inflight = blk_mq_in_flight(gp->queue, hd);
|
|
else
|
|
inflight = part_in_flight(hd);
|
|
|
|
seq_printf(seqf, "%4d %7d %s "
|
|
"%lu %lu %lu %u "
|
|
"%lu %lu %lu %u "
|
|
"%u %u %u "
|
|
"%lu %lu %lu %u "
|
|
"%lu %u"
|
|
"\n",
|
|
MAJOR(hd->bd_dev), MINOR(hd->bd_dev),
|
|
disk_name(gp, hd->bd_partno, buf),
|
|
stat.ios[STAT_READ],
|
|
stat.merges[STAT_READ],
|
|
stat.sectors[STAT_READ],
|
|
(unsigned int)div_u64(stat.nsecs[STAT_READ],
|
|
NSEC_PER_MSEC),
|
|
stat.ios[STAT_WRITE],
|
|
stat.merges[STAT_WRITE],
|
|
stat.sectors[STAT_WRITE],
|
|
(unsigned int)div_u64(stat.nsecs[STAT_WRITE],
|
|
NSEC_PER_MSEC),
|
|
inflight,
|
|
jiffies_to_msecs(stat.io_ticks),
|
|
(unsigned int)div_u64(stat.nsecs[STAT_READ] +
|
|
stat.nsecs[STAT_WRITE] +
|
|
stat.nsecs[STAT_DISCARD] +
|
|
stat.nsecs[STAT_FLUSH],
|
|
NSEC_PER_MSEC),
|
|
stat.ios[STAT_DISCARD],
|
|
stat.merges[STAT_DISCARD],
|
|
stat.sectors[STAT_DISCARD],
|
|
(unsigned int)div_u64(stat.nsecs[STAT_DISCARD],
|
|
NSEC_PER_MSEC),
|
|
stat.ios[STAT_FLUSH],
|
|
(unsigned int)div_u64(stat.nsecs[STAT_FLUSH],
|
|
NSEC_PER_MSEC)
|
|
);
|
|
}
|
|
rcu_read_unlock();
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct seq_operations diskstats_op = {
|
|
.start = disk_seqf_start,
|
|
.next = disk_seqf_next,
|
|
.stop = disk_seqf_stop,
|
|
.show = diskstats_show
|
|
};
|
|
|
|
static int __init proc_genhd_init(void)
|
|
{
|
|
proc_create_seq("diskstats", 0, NULL, &diskstats_op);
|
|
proc_create_seq("partitions", 0, NULL, &partitions_op);
|
|
return 0;
|
|
}
|
|
module_init(proc_genhd_init);
|
|
#endif /* CONFIG_PROC_FS */
|
|
|
|
dev_t blk_lookup_devt(const char *name, int partno)
|
|
{
|
|
dev_t devt = MKDEV(0, 0);
|
|
struct class_dev_iter iter;
|
|
struct device *dev;
|
|
|
|
class_dev_iter_init(&iter, &block_class, NULL, &disk_type);
|
|
while ((dev = class_dev_iter_next(&iter))) {
|
|
struct gendisk *disk = dev_to_disk(dev);
|
|
struct block_device *part;
|
|
|
|
if (strcmp(dev_name(dev), name))
|
|
continue;
|
|
|
|
if (partno < disk->minors) {
|
|
/* We need to return the right devno, even
|
|
* if the partition doesn't exist yet.
|
|
*/
|
|
devt = MKDEV(MAJOR(dev->devt),
|
|
MINOR(dev->devt) + partno);
|
|
break;
|
|
}
|
|
part = bdget_disk(disk, partno);
|
|
if (part) {
|
|
devt = part->bd_dev;
|
|
bdput(part);
|
|
break;
|
|
}
|
|
}
|
|
class_dev_iter_exit(&iter);
|
|
return devt;
|
|
}
|
|
|
|
struct gendisk *__alloc_disk_node(int minors, int node_id)
|
|
{
|
|
struct gendisk *disk;
|
|
|
|
if (minors > DISK_MAX_PARTS) {
|
|
printk(KERN_ERR
|
|
"block: can't allocate more than %d partitions\n",
|
|
DISK_MAX_PARTS);
|
|
minors = DISK_MAX_PARTS;
|
|
}
|
|
|
|
disk = kzalloc_node(sizeof(struct gendisk), GFP_KERNEL, node_id);
|
|
if (!disk)
|
|
return NULL;
|
|
|
|
disk->part0 = bdev_alloc(disk, 0);
|
|
if (!disk->part0)
|
|
goto out_free_disk;
|
|
|
|
disk->node_id = node_id;
|
|
xa_init(&disk->part_tbl);
|
|
if (xa_insert(&disk->part_tbl, 0, disk->part0, GFP_KERNEL))
|
|
goto out_destroy_part_tbl;
|
|
|
|
disk->minors = minors;
|
|
rand_initialize_disk(disk);
|
|
disk_to_dev(disk)->class = &block_class;
|
|
disk_to_dev(disk)->type = &disk_type;
|
|
device_initialize(disk_to_dev(disk));
|
|
return disk;
|
|
|
|
out_destroy_part_tbl:
|
|
xa_destroy(&disk->part_tbl);
|
|
bdput(disk->part0);
|
|
out_free_disk:
|
|
kfree(disk);
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL(__alloc_disk_node);
|
|
|
|
/**
|
|
* put_disk - decrements the gendisk refcount
|
|
* @disk: the struct gendisk to decrement the refcount for
|
|
*
|
|
* This decrements the refcount for the struct gendisk. When this reaches 0
|
|
* we'll have disk_release() called.
|
|
*
|
|
* Context: Any context, but the last reference must not be dropped from
|
|
* atomic context.
|
|
*/
|
|
void put_disk(struct gendisk *disk)
|
|
{
|
|
if (disk)
|
|
put_device(disk_to_dev(disk));
|
|
}
|
|
EXPORT_SYMBOL(put_disk);
|
|
|
|
static void set_disk_ro_uevent(struct gendisk *gd, int ro)
|
|
{
|
|
char event[] = "DISK_RO=1";
|
|
char *envp[] = { event, NULL };
|
|
|
|
if (!ro)
|
|
event[8] = '0';
|
|
kobject_uevent_env(&disk_to_dev(gd)->kobj, KOBJ_CHANGE, envp);
|
|
}
|
|
|
|
/**
|
|
* set_disk_ro - set a gendisk read-only
|
|
* @disk: gendisk to operate on
|
|
* @read_only: %true to set the disk read-only, %false set the disk read/write
|
|
*
|
|
* This function is used to indicate whether a given disk device should have its
|
|
* read-only flag set. set_disk_ro() is typically used by device drivers to
|
|
* indicate whether the underlying physical device is write-protected.
|
|
*/
|
|
void set_disk_ro(struct gendisk *disk, bool read_only)
|
|
{
|
|
if (read_only) {
|
|
if (test_and_set_bit(GD_READ_ONLY, &disk->state))
|
|
return;
|
|
} else {
|
|
if (!test_and_clear_bit(GD_READ_ONLY, &disk->state))
|
|
return;
|
|
}
|
|
set_disk_ro_uevent(disk, read_only);
|
|
}
|
|
EXPORT_SYMBOL(set_disk_ro);
|
|
|
|
int bdev_read_only(struct block_device *bdev)
|
|
{
|
|
return bdev->bd_read_only || get_disk_ro(bdev->bd_disk);
|
|
}
|
|
EXPORT_SYMBOL(bdev_read_only);
|
|
|
|
/*
|
|
* Disk events - monitor disk events like media change and eject request.
|
|
*/
|
|
struct disk_events {
|
|
struct list_head node; /* all disk_event's */
|
|
struct gendisk *disk; /* the associated disk */
|
|
spinlock_t lock;
|
|
|
|
struct mutex block_mutex; /* protects blocking */
|
|
int block; /* event blocking depth */
|
|
unsigned int pending; /* events already sent out */
|
|
unsigned int clearing; /* events being cleared */
|
|
|
|
long poll_msecs; /* interval, -1 for default */
|
|
struct delayed_work dwork;
|
|
};
|
|
|
|
static const char *disk_events_strs[] = {
|
|
[ilog2(DISK_EVENT_MEDIA_CHANGE)] = "media_change",
|
|
[ilog2(DISK_EVENT_EJECT_REQUEST)] = "eject_request",
|
|
};
|
|
|
|
static char *disk_uevents[] = {
|
|
[ilog2(DISK_EVENT_MEDIA_CHANGE)] = "DISK_MEDIA_CHANGE=1",
|
|
[ilog2(DISK_EVENT_EJECT_REQUEST)] = "DISK_EJECT_REQUEST=1",
|
|
};
|
|
|
|
/* list of all disk_events */
|
|
static DEFINE_MUTEX(disk_events_mutex);
|
|
static LIST_HEAD(disk_events);
|
|
|
|
/* disable in-kernel polling by default */
|
|
static unsigned long disk_events_dfl_poll_msecs;
|
|
|
|
static unsigned long disk_events_poll_jiffies(struct gendisk *disk)
|
|
{
|
|
struct disk_events *ev = disk->ev;
|
|
long intv_msecs = 0;
|
|
|
|
/*
|
|
* If device-specific poll interval is set, always use it. If
|
|
* the default is being used, poll if the POLL flag is set.
|
|
*/
|
|
if (ev->poll_msecs >= 0)
|
|
intv_msecs = ev->poll_msecs;
|
|
else if (disk->event_flags & DISK_EVENT_FLAG_POLL)
|
|
intv_msecs = disk_events_dfl_poll_msecs;
|
|
|
|
return msecs_to_jiffies(intv_msecs);
|
|
}
|
|
|
|
/**
|
|
* disk_block_events - block and flush disk event checking
|
|
* @disk: disk to block events for
|
|
*
|
|
* On return from this function, it is guaranteed that event checking
|
|
* isn't in progress and won't happen until unblocked by
|
|
* disk_unblock_events(). Events blocking is counted and the actual
|
|
* unblocking happens after the matching number of unblocks are done.
|
|
*
|
|
* Note that this intentionally does not block event checking from
|
|
* disk_clear_events().
|
|
*
|
|
* CONTEXT:
|
|
* Might sleep.
|
|
*/
|
|
void disk_block_events(struct gendisk *disk)
|
|
{
|
|
struct disk_events *ev = disk->ev;
|
|
unsigned long flags;
|
|
bool cancel;
|
|
|
|
if (!ev)
|
|
return;
|
|
|
|
/*
|
|
* Outer mutex ensures that the first blocker completes canceling
|
|
* the event work before further blockers are allowed to finish.
|
|
*/
|
|
mutex_lock(&ev->block_mutex);
|
|
|
|
spin_lock_irqsave(&ev->lock, flags);
|
|
cancel = !ev->block++;
|
|
spin_unlock_irqrestore(&ev->lock, flags);
|
|
|
|
if (cancel)
|
|
cancel_delayed_work_sync(&disk->ev->dwork);
|
|
|
|
mutex_unlock(&ev->block_mutex);
|
|
}
|
|
|
|
static void __disk_unblock_events(struct gendisk *disk, bool check_now)
|
|
{
|
|
struct disk_events *ev = disk->ev;
|
|
unsigned long intv;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&ev->lock, flags);
|
|
|
|
if (WARN_ON_ONCE(ev->block <= 0))
|
|
goto out_unlock;
|
|
|
|
if (--ev->block)
|
|
goto out_unlock;
|
|
|
|
intv = disk_events_poll_jiffies(disk);
|
|
if (check_now)
|
|
queue_delayed_work(system_freezable_power_efficient_wq,
|
|
&ev->dwork, 0);
|
|
else if (intv)
|
|
queue_delayed_work(system_freezable_power_efficient_wq,
|
|
&ev->dwork, intv);
|
|
out_unlock:
|
|
spin_unlock_irqrestore(&ev->lock, flags);
|
|
}
|
|
|
|
/**
|
|
* disk_unblock_events - unblock disk event checking
|
|
* @disk: disk to unblock events for
|
|
*
|
|
* Undo disk_block_events(). When the block count reaches zero, it
|
|
* starts events polling if configured.
|
|
*
|
|
* CONTEXT:
|
|
* Don't care. Safe to call from irq context.
|
|
*/
|
|
void disk_unblock_events(struct gendisk *disk)
|
|
{
|
|
if (disk->ev)
|
|
__disk_unblock_events(disk, false);
|
|
}
|
|
|
|
/**
|
|
* disk_flush_events - schedule immediate event checking and flushing
|
|
* @disk: disk to check and flush events for
|
|
* @mask: events to flush
|
|
*
|
|
* Schedule immediate event checking on @disk if not blocked. Events in
|
|
* @mask are scheduled to be cleared from the driver. Note that this
|
|
* doesn't clear the events from @disk->ev.
|
|
*
|
|
* CONTEXT:
|
|
* If @mask is non-zero must be called with bdev->bd_mutex held.
|
|
*/
|
|
void disk_flush_events(struct gendisk *disk, unsigned int mask)
|
|
{
|
|
struct disk_events *ev = disk->ev;
|
|
|
|
if (!ev)
|
|
return;
|
|
|
|
spin_lock_irq(&ev->lock);
|
|
ev->clearing |= mask;
|
|
if (!ev->block)
|
|
mod_delayed_work(system_freezable_power_efficient_wq,
|
|
&ev->dwork, 0);
|
|
spin_unlock_irq(&ev->lock);
|
|
}
|
|
|
|
/**
|
|
* disk_clear_events - synchronously check, clear and return pending events
|
|
* @disk: disk to fetch and clear events from
|
|
* @mask: mask of events to be fetched and cleared
|
|
*
|
|
* Disk events are synchronously checked and pending events in @mask
|
|
* are cleared and returned. This ignores the block count.
|
|
*
|
|
* CONTEXT:
|
|
* Might sleep.
|
|
*/
|
|
static unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask)
|
|
{
|
|
struct disk_events *ev = disk->ev;
|
|
unsigned int pending;
|
|
unsigned int clearing = mask;
|
|
|
|
if (!ev)
|
|
return 0;
|
|
|
|
disk_block_events(disk);
|
|
|
|
/*
|
|
* store the union of mask and ev->clearing on the stack so that the
|
|
* race with disk_flush_events does not cause ambiguity (ev->clearing
|
|
* can still be modified even if events are blocked).
|
|
*/
|
|
spin_lock_irq(&ev->lock);
|
|
clearing |= ev->clearing;
|
|
ev->clearing = 0;
|
|
spin_unlock_irq(&ev->lock);
|
|
|
|
disk_check_events(ev, &clearing);
|
|
/*
|
|
* if ev->clearing is not 0, the disk_flush_events got called in the
|
|
* middle of this function, so we want to run the workfn without delay.
|
|
*/
|
|
__disk_unblock_events(disk, ev->clearing ? true : false);
|
|
|
|
/* then, fetch and clear pending events */
|
|
spin_lock_irq(&ev->lock);
|
|
pending = ev->pending & mask;
|
|
ev->pending &= ~mask;
|
|
spin_unlock_irq(&ev->lock);
|
|
WARN_ON_ONCE(clearing & mask);
|
|
|
|
return pending;
|
|
}
|
|
|
|
/**
|
|
* bdev_check_media_change - check if a removable media has been changed
|
|
* @bdev: block device to check
|
|
*
|
|
* Check whether a removable media has been changed, and attempt to free all
|
|
* dentries and inodes and invalidates all block device page cache entries in
|
|
* that case.
|
|
*
|
|
* Returns %true if the block device changed, or %false if not.
|
|
*/
|
|
bool bdev_check_media_change(struct block_device *bdev)
|
|
{
|
|
unsigned int events;
|
|
|
|
events = disk_clear_events(bdev->bd_disk, DISK_EVENT_MEDIA_CHANGE |
|
|
DISK_EVENT_EJECT_REQUEST);
|
|
if (!(events & DISK_EVENT_MEDIA_CHANGE))
|
|
return false;
|
|
|
|
if (__invalidate_device(bdev, true))
|
|
pr_warn("VFS: busy inodes on changed media %s\n",
|
|
bdev->bd_disk->disk_name);
|
|
set_bit(GD_NEED_PART_SCAN, &bdev->bd_disk->state);
|
|
return true;
|
|
}
|
|
EXPORT_SYMBOL(bdev_check_media_change);
|
|
|
|
/*
|
|
* Separate this part out so that a different pointer for clearing_ptr can be
|
|
* passed in for disk_clear_events.
|
|
*/
|
|
static void disk_events_workfn(struct work_struct *work)
|
|
{
|
|
struct delayed_work *dwork = to_delayed_work(work);
|
|
struct disk_events *ev = container_of(dwork, struct disk_events, dwork);
|
|
|
|
disk_check_events(ev, &ev->clearing);
|
|
}
|
|
|
|
static void disk_check_events(struct disk_events *ev,
|
|
unsigned int *clearing_ptr)
|
|
{
|
|
struct gendisk *disk = ev->disk;
|
|
char *envp[ARRAY_SIZE(disk_uevents) + 1] = { };
|
|
unsigned int clearing = *clearing_ptr;
|
|
unsigned int events;
|
|
unsigned long intv;
|
|
int nr_events = 0, i;
|
|
|
|
/* check events */
|
|
events = disk->fops->check_events(disk, clearing);
|
|
|
|
/* accumulate pending events and schedule next poll if necessary */
|
|
spin_lock_irq(&ev->lock);
|
|
|
|
events &= ~ev->pending;
|
|
ev->pending |= events;
|
|
*clearing_ptr &= ~clearing;
|
|
|
|
intv = disk_events_poll_jiffies(disk);
|
|
if (!ev->block && intv)
|
|
queue_delayed_work(system_freezable_power_efficient_wq,
|
|
&ev->dwork, intv);
|
|
|
|
spin_unlock_irq(&ev->lock);
|
|
|
|
/*
|
|
* Tell userland about new events. Only the events listed in
|
|
* @disk->events are reported, and only if DISK_EVENT_FLAG_UEVENT
|
|
* is set. Otherwise, events are processed internally but never
|
|
* get reported to userland.
|
|
*/
|
|
for (i = 0; i < ARRAY_SIZE(disk_uevents); i++)
|
|
if ((events & disk->events & (1 << i)) &&
|
|
(disk->event_flags & DISK_EVENT_FLAG_UEVENT))
|
|
envp[nr_events++] = disk_uevents[i];
|
|
|
|
if (nr_events)
|
|
kobject_uevent_env(&disk_to_dev(disk)->kobj, KOBJ_CHANGE, envp);
|
|
}
|
|
|
|
/*
|
|
* A disk events enabled device has the following sysfs nodes under
|
|
* its /sys/block/X/ directory.
|
|
*
|
|
* events : list of all supported events
|
|
* events_async : list of events which can be detected w/o polling
|
|
* (always empty, only for backwards compatibility)
|
|
* events_poll_msecs : polling interval, 0: disable, -1: system default
|
|
*/
|
|
static ssize_t __disk_events_show(unsigned int events, char *buf)
|
|
{
|
|
const char *delim = "";
|
|
ssize_t pos = 0;
|
|
int i;
|
|
|
|
for (i = 0; i < ARRAY_SIZE(disk_events_strs); i++)
|
|
if (events & (1 << i)) {
|
|
pos += sprintf(buf + pos, "%s%s",
|
|
delim, disk_events_strs[i]);
|
|
delim = " ";
|
|
}
|
|
if (pos)
|
|
pos += sprintf(buf + pos, "\n");
|
|
return pos;
|
|
}
|
|
|
|
static ssize_t disk_events_show(struct device *dev,
|
|
struct device_attribute *attr, char *buf)
|
|
{
|
|
struct gendisk *disk = dev_to_disk(dev);
|
|
|
|
if (!(disk->event_flags & DISK_EVENT_FLAG_UEVENT))
|
|
return 0;
|
|
|
|
return __disk_events_show(disk->events, buf);
|
|
}
|
|
|
|
static ssize_t disk_events_async_show(struct device *dev,
|
|
struct device_attribute *attr, char *buf)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static ssize_t disk_events_poll_msecs_show(struct device *dev,
|
|
struct device_attribute *attr,
|
|
char *buf)
|
|
{
|
|
struct gendisk *disk = dev_to_disk(dev);
|
|
|
|
if (!disk->ev)
|
|
return sprintf(buf, "-1\n");
|
|
|
|
return sprintf(buf, "%ld\n", disk->ev->poll_msecs);
|
|
}
|
|
|
|
static ssize_t disk_events_poll_msecs_store(struct device *dev,
|
|
struct device_attribute *attr,
|
|
const char *buf, size_t count)
|
|
{
|
|
struct gendisk *disk = dev_to_disk(dev);
|
|
long intv;
|
|
|
|
if (!count || !sscanf(buf, "%ld", &intv))
|
|
return -EINVAL;
|
|
|
|
if (intv < 0 && intv != -1)
|
|
return -EINVAL;
|
|
|
|
if (!disk->ev)
|
|
return -ENODEV;
|
|
|
|
disk_block_events(disk);
|
|
disk->ev->poll_msecs = intv;
|
|
__disk_unblock_events(disk, true);
|
|
|
|
return count;
|
|
}
|
|
|
|
static const DEVICE_ATTR(events, 0444, disk_events_show, NULL);
|
|
static const DEVICE_ATTR(events_async, 0444, disk_events_async_show, NULL);
|
|
static const DEVICE_ATTR(events_poll_msecs, 0644,
|
|
disk_events_poll_msecs_show,
|
|
disk_events_poll_msecs_store);
|
|
|
|
static const struct attribute *disk_events_attrs[] = {
|
|
&dev_attr_events.attr,
|
|
&dev_attr_events_async.attr,
|
|
&dev_attr_events_poll_msecs.attr,
|
|
NULL,
|
|
};
|
|
|
|
/*
|
|
* The default polling interval can be specified by the kernel
|
|
* parameter block.events_dfl_poll_msecs which defaults to 0
|
|
* (disable). This can also be modified runtime by writing to
|
|
* /sys/module/block/parameters/events_dfl_poll_msecs.
|
|
*/
|
|
static int disk_events_set_dfl_poll_msecs(const char *val,
|
|
const struct kernel_param *kp)
|
|
{
|
|
struct disk_events *ev;
|
|
int ret;
|
|
|
|
ret = param_set_ulong(val, kp);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
mutex_lock(&disk_events_mutex);
|
|
|
|
list_for_each_entry(ev, &disk_events, node)
|
|
disk_flush_events(ev->disk, 0);
|
|
|
|
mutex_unlock(&disk_events_mutex);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct kernel_param_ops disk_events_dfl_poll_msecs_param_ops = {
|
|
.set = disk_events_set_dfl_poll_msecs,
|
|
.get = param_get_ulong,
|
|
};
|
|
|
|
#undef MODULE_PARAM_PREFIX
|
|
#define MODULE_PARAM_PREFIX "block."
|
|
|
|
module_param_cb(events_dfl_poll_msecs, &disk_events_dfl_poll_msecs_param_ops,
|
|
&disk_events_dfl_poll_msecs, 0644);
|
|
|
|
/*
|
|
* disk_{alloc|add|del|release}_events - initialize and destroy disk_events.
|
|
*/
|
|
static void disk_alloc_events(struct gendisk *disk)
|
|
{
|
|
struct disk_events *ev;
|
|
|
|
if (!disk->fops->check_events || !disk->events)
|
|
return;
|
|
|
|
ev = kzalloc(sizeof(*ev), GFP_KERNEL);
|
|
if (!ev) {
|
|
pr_warn("%s: failed to initialize events\n", disk->disk_name);
|
|
return;
|
|
}
|
|
|
|
INIT_LIST_HEAD(&ev->node);
|
|
ev->disk = disk;
|
|
spin_lock_init(&ev->lock);
|
|
mutex_init(&ev->block_mutex);
|
|
ev->block = 1;
|
|
ev->poll_msecs = -1;
|
|
INIT_DELAYED_WORK(&ev->dwork, disk_events_workfn);
|
|
|
|
disk->ev = ev;
|
|
}
|
|
|
|
static void disk_add_events(struct gendisk *disk)
|
|
{
|
|
/* FIXME: error handling */
|
|
if (sysfs_create_files(&disk_to_dev(disk)->kobj, disk_events_attrs) < 0)
|
|
pr_warn("%s: failed to create sysfs files for events\n",
|
|
disk->disk_name);
|
|
|
|
if (!disk->ev)
|
|
return;
|
|
|
|
mutex_lock(&disk_events_mutex);
|
|
list_add_tail(&disk->ev->node, &disk_events);
|
|
mutex_unlock(&disk_events_mutex);
|
|
|
|
/*
|
|
* Block count is initialized to 1 and the following initial
|
|
* unblock kicks it into action.
|
|
*/
|
|
__disk_unblock_events(disk, true);
|
|
}
|
|
|
|
static void disk_del_events(struct gendisk *disk)
|
|
{
|
|
if (disk->ev) {
|
|
disk_block_events(disk);
|
|
|
|
mutex_lock(&disk_events_mutex);
|
|
list_del_init(&disk->ev->node);
|
|
mutex_unlock(&disk_events_mutex);
|
|
}
|
|
|
|
sysfs_remove_files(&disk_to_dev(disk)->kobj, disk_events_attrs);
|
|
}
|
|
|
|
static void disk_release_events(struct gendisk *disk)
|
|
{
|
|
/* the block count should be 1 from disk_del_events() */
|
|
WARN_ON_ONCE(disk->ev && disk->ev->block != 1);
|
|
kfree(disk->ev);
|
|
}
|