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1940 lines
48 KiB
1940 lines
48 KiB
// 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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|
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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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* disk_part_iter_init - initialize partition iterator |
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* @piter: iterator to initialize |
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* @disk: disk to iterate over |
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* @flags: DISK_PITER_* flags |
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* |
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* Initialize @piter so that it iterates over partitions of @disk. |
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* |
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* CONTEXT: |
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* Don't care. |
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*/ |
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void disk_part_iter_init(struct disk_part_iter *piter, struct gendisk *disk, |
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unsigned int flags) |
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{ |
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piter->disk = disk; |
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piter->part = NULL; |
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if (flags & (DISK_PITER_INCL_PART0 | DISK_PITER_INCL_EMPTY_PART0)) |
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piter->idx = 0; |
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else |
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piter->idx = 1; |
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piter->flags = flags; |
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} |
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/** |
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* disk_part_iter_next - proceed iterator to the next partition and return it |
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* @piter: iterator of interest |
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* |
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* Proceed @piter to the next partition and return it. |
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* |
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* CONTEXT: |
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* Don't care. |
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*/ |
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struct block_device *disk_part_iter_next(struct disk_part_iter *piter) |
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{ |
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struct block_device *part; |
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unsigned long idx; |
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/* put the last partition */ |
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disk_part_iter_exit(piter); |
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rcu_read_lock(); |
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xa_for_each_start(&piter->disk->part_tbl, idx, part, piter->idx) { |
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if (!bdev_nr_sectors(part) && |
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!(piter->flags & DISK_PITER_INCL_EMPTY) && |
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!(piter->flags & DISK_PITER_INCL_EMPTY_PART0 && |
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piter->idx == 0)) |
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continue; |
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piter->part = bdgrab(part); |
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if (!piter->part) |
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continue; |
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piter->idx = idx + 1; |
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break; |
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} |
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rcu_read_unlock(); |
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return piter->part; |
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} |
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/** |
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* disk_part_iter_exit - finish up partition iteration |
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* @piter: iter of interest |
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* |
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* Called when iteration is over. Cleans up @piter. |
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* |
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* CONTEXT: |
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* Don't care. |
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*/ |
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void disk_part_iter_exit(struct disk_part_iter *piter) |
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{ |
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if (piter->part) |
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bdput(piter->part); |
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piter->part = NULL; |
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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 disk_part_iter piter; |
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struct block_device *part; |
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disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY_PART0); |
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while ((part = disk_part_iter_next(&piter))) |
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kobject_uevent(bdev_kobj(part), action); |
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disk_part_iter_exit(&piter); |
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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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* 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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if (disk->flags & GENHD_FL_HIDDEN) |
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return; |
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disk_scan_partitions(disk); |
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|
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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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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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/* |
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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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*/ |
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if (register_queue) |
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elevator_init_mq(disk->queue); |
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|
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/* minors == 0 indicates to use ext devt from part0 and should |
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* be accompanied with EXT_DEVT flag. Make sure all |
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* parameters make sense. |
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*/ |
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WARN_ON(disk->minors && !(disk->major || disk->first_minor)); |
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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); |
|
|
|
static void invalidate_partition(struct block_device *bdev) |
|
{ |
|
fsync_bdev(bdev); |
|
__invalidate_device(bdev, 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(bdev->bd_inode); |
|
} |
|
|
|
/** |
|
* 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) |
|
{ |
|
struct disk_part_iter piter; |
|
struct block_device *part; |
|
|
|
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); |
|
|
|
/* invalidate stuff */ |
|
disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY); |
|
while ((part = disk_part_iter_next(&piter))) { |
|
invalidate_partition(part); |
|
delete_partition(part); |
|
} |
|
disk_part_iter_exit(&piter); |
|
|
|
invalidate_partition(disk->part0); |
|
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 disk_part_iter piter; |
|
struct block_device *part; |
|
char name_buf[BDEVNAME_SIZE]; |
|
char devt_buf[BDEVT_SIZE]; |
|
|
|
/* |
|
* 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. |
|
*/ |
|
disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0); |
|
while ((part = disk_part_iter_next(&piter))) { |
|
bool is_part0 = part == disk->part0; |
|
|
|
printk("%s%s %10llu %s %s", is_part0 ? "" : " ", |
|
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 (is_part0) { |
|
if (dev->parent && dev->parent->driver) |
|
printk(" driver: %s\n", |
|
dev->parent->driver->name); |
|
else |
|
printk(" (driver?)\n"); |
|
} else |
|
printk("\n"); |
|
} |
|
disk_part_iter_exit(&piter); |
|
} |
|
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 disk_part_iter piter; |
|
struct block_device *part; |
|
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; |
|
|
|
/* show the full disk and all non-0 size partitions of it */ |
|
disk_part_iter_init(&piter, sgp, DISK_PITER_INCL_PART0); |
|
while ((part = disk_part_iter_next(&piter))) |
|
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)); |
|
disk_part_iter_exit(&piter); |
|
|
|
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 disk_part_iter piter; |
|
struct block_device *hd; |
|
char buf[BDEVNAME_SIZE]; |
|
unsigned int inflight; |
|
struct disk_stats stat; |
|
|
|
/* |
|
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"); |
|
*/ |
|
|
|
disk_part_iter_init(&piter, gp, DISK_PITER_INCL_EMPTY_PART0); |
|
while ((hd = disk_part_iter_next(&piter))) { |
|
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) |
|
); |
|
} |
|
disk_part_iter_exit(&piter); |
|
|
|
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); |
|
}
|
|
|