This patch fixes the checkpatch.pl error to genhd.c: ERROR: do not initialise statics to 0 or NULL Signed-off-by: Wei Tang <tangwei@cmss.chinamobile.com> Signed-off-by: Jens Axboe <axboe@fb.com>
1851 lines
44 KiB
C
1851 lines
44 KiB
C
/*
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* gendisk handling
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*/
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#include <linux/module.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/kobj_map.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 "blk.h"
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static DEFINE_MUTEX(block_class_lock);
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struct kobject *block_depr;
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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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/* For extended devt allocation. ext_devt_lock prevents look up
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* results from going away underneath its user.
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*/
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static DEFINE_SPINLOCK(ext_devt_lock);
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static DEFINE_IDR(ext_devt_idr);
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static struct device_type disk_type;
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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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/**
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* disk_get_part - get partition
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* @disk: disk to look partition from
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* @partno: partition number
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*
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* Look for partition @partno from @disk. If found, increment
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* reference count 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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* RETURNS:
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* Pointer to the found partition on success, NULL if not found.
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*/
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struct hd_struct *disk_get_part(struct gendisk *disk, int partno)
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{
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struct hd_struct *part = NULL;
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struct disk_part_tbl *ptbl;
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if (unlikely(partno < 0))
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return NULL;
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rcu_read_lock();
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ptbl = rcu_dereference(disk->part_tbl);
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if (likely(partno < ptbl->len)) {
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part = rcu_dereference(ptbl->part[partno]);
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if (part)
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get_device(part_to_dev(part));
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}
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rcu_read_unlock();
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return part;
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}
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EXPORT_SYMBOL_GPL(disk_get_part);
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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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struct disk_part_tbl *ptbl;
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rcu_read_lock();
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ptbl = rcu_dereference(disk->part_tbl);
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piter->disk = disk;
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piter->part = NULL;
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if (flags & DISK_PITER_REVERSE)
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piter->idx = ptbl->len - 1;
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else 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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rcu_read_unlock();
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}
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EXPORT_SYMBOL_GPL(disk_part_iter_init);
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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 hd_struct *disk_part_iter_next(struct disk_part_iter *piter)
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{
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struct disk_part_tbl *ptbl;
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int inc, end;
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/* put the last partition */
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disk_put_part(piter->part);
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piter->part = NULL;
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/* get part_tbl */
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rcu_read_lock();
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ptbl = rcu_dereference(piter->disk->part_tbl);
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/* determine iteration parameters */
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if (piter->flags & DISK_PITER_REVERSE) {
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inc = -1;
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if (piter->flags & (DISK_PITER_INCL_PART0 |
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DISK_PITER_INCL_EMPTY_PART0))
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end = -1;
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else
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end = 0;
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} else {
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inc = 1;
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end = ptbl->len;
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}
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/* iterate to the next partition */
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for (; piter->idx != end; piter->idx += inc) {
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struct hd_struct *part;
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part = rcu_dereference(ptbl->part[piter->idx]);
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if (!part)
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continue;
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if (!part_nr_sects_read(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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get_device(part_to_dev(part));
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piter->part = part;
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piter->idx += inc;
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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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EXPORT_SYMBOL_GPL(disk_part_iter_next);
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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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disk_put_part(piter->part);
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piter->part = NULL;
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}
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EXPORT_SYMBOL_GPL(disk_part_iter_exit);
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static inline int sector_in_part(struct hd_struct *part, sector_t sector)
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{
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return part->start_sect <= sector &&
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sector < part->start_sect + part_nr_sects_read(part);
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}
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/**
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* disk_map_sector_rcu - map sector to partition
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* @disk: gendisk of interest
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* @sector: sector to map
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*
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* Find out which partition @sector maps to on @disk. This is
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* primarily used for stats accounting.
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*
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* CONTEXT:
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* RCU read locked. The returned partition pointer is valid only
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* while preemption is disabled.
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*
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* RETURNS:
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* Found partition on success, part0 is returned if no partition matches
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*/
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struct hd_struct *disk_map_sector_rcu(struct gendisk *disk, sector_t sector)
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{
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struct disk_part_tbl *ptbl;
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struct hd_struct *part;
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int i;
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ptbl = rcu_dereference(disk->part_tbl);
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part = rcu_dereference(ptbl->last_lookup);
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if (part && sector_in_part(part, sector))
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return part;
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for (i = 1; i < ptbl->len; i++) {
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part = rcu_dereference(ptbl->part[i]);
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if (part && sector_in_part(part, sector)) {
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rcu_assign_pointer(ptbl->last_lookup, part);
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return part;
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}
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}
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return &disk->part0;
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}
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EXPORT_SYMBOL_GPL(disk_map_sector_rcu);
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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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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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} *major_names[BLKDEV_MAJOR_HASH_SIZE];
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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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if (offset < BLKDEV_MAJOR_HASH_SIZE) {
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mutex_lock(&block_class_lock);
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for (dp = major_names[offset]; dp; dp = dp->next)
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seq_printf(seqf, "%3d %s\n", dp->major, dp->name);
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mutex_unlock(&block_class_lock);
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}
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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..255]. If @major=0, try to
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* 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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*
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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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* - if a major device number was requested in range [1..255] then the
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* 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..255] or a negative error code otherwise
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*/
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int register_blkdev(unsigned int major, const char *name)
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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(&block_class_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("register_blkdev: failed to get major for %s\n",
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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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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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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 %d 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(&block_class_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(&block_class_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(&block_class_lock);
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kfree(p);
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}
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EXPORT_SYMBOL(unregister_blkdev);
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static struct kobj_map *bdev_map;
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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 partition
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* @part: partition 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 hd_struct *part, dev_t *devt)
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{
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struct gendisk *disk = part_to_disk(part);
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int idx;
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/* in consecutive minor range? */
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if (part->partno < disk->minors) {
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*devt = MKDEV(disk->major, disk->first_minor + part->partno);
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return 0;
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}
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/* allocate ext devt */
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idr_preload(GFP_KERNEL);
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spin_lock_bh(&ext_devt_lock);
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idx = idr_alloc(&ext_devt_idr, part, 0, NR_EXT_DEVT, GFP_NOWAIT);
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spin_unlock_bh(&ext_devt_lock);
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idr_preload_end();
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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 (devt == MKDEV(0, 0))
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return;
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if (MAJOR(devt) == BLOCK_EXT_MAJOR) {
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spin_lock_bh(&ext_devt_lock);
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idr_remove(&ext_devt_idr, blk_mangle_minor(MINOR(devt)));
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spin_unlock_bh(&ext_devt_lock);
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}
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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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/*
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* Register device numbers dev..(dev+range-1)
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* range must be nonzero
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* The hash chain is sorted on range, so that subranges can override.
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*/
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void blk_register_region(dev_t devt, unsigned long range, struct module *module,
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struct kobject *(*probe)(dev_t, int *, void *),
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int (*lock)(dev_t, void *), void *data)
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{
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kobj_map(bdev_map, devt, range, module, probe, lock, data);
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}
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EXPORT_SYMBOL(blk_register_region);
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void blk_unregister_region(dev_t devt, unsigned long range)
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{
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kobj_unmap(bdev_map, devt, range);
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}
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EXPORT_SYMBOL(blk_unregister_region);
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static struct kobject *exact_match(dev_t devt, int *partno, void *data)
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{
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struct gendisk *p = data;
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return &disk_to_dev(p)->kobj;
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}
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static int exact_lock(dev_t devt, void *data)
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{
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struct gendisk *p = data;
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if (!get_disk(p))
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return -1;
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return 0;
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}
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static void register_disk(struct gendisk *disk)
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{
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struct device *ddev = disk_to_dev(disk);
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struct block_device *bdev;
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struct disk_part_iter piter;
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struct hd_struct *part;
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int err;
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ddev->parent = disk->driverfs_dev;
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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 (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.holder_dir = kobject_create_and_add("holders", &ddev->kobj);
|
|
disk->slave_dir = kobject_create_and_add("slaves", &ddev->kobj);
|
|
|
|
/* No minors to use for partitions */
|
|
if (!disk_part_scan_enabled(disk))
|
|
goto exit;
|
|
|
|
/* No such device (e.g., media were just removed) */
|
|
if (!get_capacity(disk))
|
|
goto exit;
|
|
|
|
bdev = bdget_disk(disk, 0);
|
|
if (!bdev)
|
|
goto exit;
|
|
|
|
bdev->bd_invalidated = 1;
|
|
err = blkdev_get(bdev, FMODE_READ, NULL);
|
|
if (err < 0)
|
|
goto exit;
|
|
blkdev_put(bdev, FMODE_READ);
|
|
|
|
exit:
|
|
/* announce disk after possible partitions are created */
|
|
dev_set_uevent_suppress(ddev, 0);
|
|
kobject_uevent(&ddev->kobj, KOBJ_ADD);
|
|
|
|
/* announce possible partitions */
|
|
disk_part_iter_init(&piter, disk, 0);
|
|
while ((part = disk_part_iter_next(&piter)))
|
|
kobject_uevent(&part_to_dev(part)->kobj, KOBJ_ADD);
|
|
disk_part_iter_exit(&piter);
|
|
}
|
|
|
|
/**
|
|
* add_disk - add partitioning information to kernel list
|
|
* @disk: per-device partitioning information
|
|
*
|
|
* This function registers the partitioning information in @disk
|
|
* with the kernel.
|
|
*
|
|
* FIXME: error handling
|
|
*/
|
|
void add_disk(struct gendisk *disk)
|
|
{
|
|
struct backing_dev_info *bdi;
|
|
dev_t devt;
|
|
int retval;
|
|
|
|
/* 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));
|
|
|
|
disk->flags |= GENHD_FL_UP;
|
|
|
|
retval = blk_alloc_devt(&disk->part0, &devt);
|
|
if (retval) {
|
|
WARN_ON(1);
|
|
return;
|
|
}
|
|
disk_to_dev(disk)->devt = devt;
|
|
|
|
/* ->major and ->first_minor aren't supposed to be
|
|
* dereferenced from here on, but set them just in case.
|
|
*/
|
|
disk->major = MAJOR(devt);
|
|
disk->first_minor = MINOR(devt);
|
|
|
|
disk_alloc_events(disk);
|
|
|
|
/* Register BDI before referencing it from bdev */
|
|
bdi = &disk->queue->backing_dev_info;
|
|
bdi_register_dev(bdi, disk_devt(disk));
|
|
|
|
blk_register_region(disk_devt(disk), disk->minors, NULL,
|
|
exact_match, exact_lock, disk);
|
|
register_disk(disk);
|
|
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));
|
|
|
|
retval = sysfs_create_link(&disk_to_dev(disk)->kobj, &bdi->dev->kobj,
|
|
"bdi");
|
|
WARN_ON(retval);
|
|
|
|
disk_add_events(disk);
|
|
blk_integrity_add(disk);
|
|
}
|
|
EXPORT_SYMBOL(add_disk);
|
|
|
|
void del_gendisk(struct gendisk *disk)
|
|
{
|
|
struct disk_part_iter piter;
|
|
struct hd_struct *part;
|
|
|
|
blk_integrity_del(disk);
|
|
disk_del_events(disk);
|
|
|
|
/* invalidate stuff */
|
|
disk_part_iter_init(&piter, disk,
|
|
DISK_PITER_INCL_EMPTY | DISK_PITER_REVERSE);
|
|
while ((part = disk_part_iter_next(&piter))) {
|
|
invalidate_partition(disk, part->partno);
|
|
delete_partition(disk, part->partno);
|
|
}
|
|
disk_part_iter_exit(&piter);
|
|
|
|
invalidate_partition(disk, 0);
|
|
set_capacity(disk, 0);
|
|
disk->flags &= ~GENHD_FL_UP;
|
|
|
|
sysfs_remove_link(&disk_to_dev(disk)->kobj, "bdi");
|
|
blk_unregister_queue(disk);
|
|
blk_unregister_region(disk_devt(disk), disk->minors);
|
|
|
|
part_stat_set_all(&disk->part0, 0);
|
|
disk->part0.stamp = 0;
|
|
|
|
kobject_put(disk->part0.holder_dir);
|
|
kobject_put(disk->slave_dir);
|
|
disk->driverfs_dev = NULL;
|
|
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);
|
|
|
|
/**
|
|
* get_gendisk - get partitioning information for a given device
|
|
* @devt: device to get partitioning information for
|
|
* @partno: returned partition index
|
|
*
|
|
* This function gets the structure containing partitioning
|
|
* information for the given device @devt.
|
|
*/
|
|
struct gendisk *get_gendisk(dev_t devt, int *partno)
|
|
{
|
|
struct gendisk *disk = NULL;
|
|
|
|
if (MAJOR(devt) != BLOCK_EXT_MAJOR) {
|
|
struct kobject *kobj;
|
|
|
|
kobj = kobj_lookup(bdev_map, devt, partno);
|
|
if (kobj)
|
|
disk = dev_to_disk(kobj_to_dev(kobj));
|
|
} else {
|
|
struct hd_struct *part;
|
|
|
|
spin_lock_bh(&ext_devt_lock);
|
|
part = idr_find(&ext_devt_idr, blk_mangle_minor(MINOR(devt)));
|
|
if (part && get_disk(part_to_disk(part))) {
|
|
*partno = part->partno;
|
|
disk = part_to_disk(part);
|
|
}
|
|
spin_unlock_bh(&ext_devt_lock);
|
|
}
|
|
|
|
return disk;
|
|
}
|
|
EXPORT_SYMBOL(get_gendisk);
|
|
|
|
/**
|
|
* 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 hd_struct *part;
|
|
struct block_device *bdev = NULL;
|
|
|
|
part = disk_get_part(disk, partno);
|
|
if (part)
|
|
bdev = bdget(part_devt(part));
|
|
disk_put_part(part);
|
|
|
|
return bdev;
|
|
}
|
|
EXPORT_SYMBOL(bdget_disk);
|
|
|
|
/*
|
|
* 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 hd_struct *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_devt(part), devt_buf),
|
|
(unsigned long long)part_nr_sects_read(part) >> 1
|
|
, disk_name(disk, part->partno, name_buf),
|
|
part->info ? part->info->uuid : "");
|
|
if (is_part0) {
|
|
if (disk->driverfs_dev != NULL &&
|
|
disk->driverfs_dev->driver != NULL)
|
|
printk(" driver: %s\n",
|
|
disk->driverfs_dev->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);
|
|
}
|
|
}
|
|
|
|
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 hd_struct *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_devt(part)), MINOR(part_devt(part)),
|
|
(unsigned long long)part_nr_sects_read(part) >> 1,
|
|
disk_name(sgp, part->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
|
|
};
|
|
|
|
static int partitions_open(struct inode *inode, struct file *file)
|
|
{
|
|
return seq_open(file, &partitions_op);
|
|
}
|
|
|
|
static const struct file_operations proc_partitions_operations = {
|
|
.open = partitions_open,
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = seq_release,
|
|
};
|
|
#endif
|
|
|
|
|
|
static struct kobject *base_probe(dev_t devt, int *partno, void *data)
|
|
{
|
|
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));
|
|
return NULL;
|
|
}
|
|
|
|
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;
|
|
bdev_map = kobj_map_init(base_probe, &block_class_lock);
|
|
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_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);
|
|
}
|
|
|
|
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, S_IRUGO, disk_range_show, NULL);
|
|
static DEVICE_ATTR(ext_range, S_IRUGO, disk_ext_range_show, NULL);
|
|
static DEVICE_ATTR(removable, S_IRUGO, disk_removable_show, NULL);
|
|
static DEVICE_ATTR(ro, S_IRUGO, disk_ro_show, NULL);
|
|
static DEVICE_ATTR(size, S_IRUGO, part_size_show, NULL);
|
|
static DEVICE_ATTR(alignment_offset, S_IRUGO, disk_alignment_offset_show, NULL);
|
|
static DEVICE_ATTR(discard_alignment, S_IRUGO, disk_discard_alignment_show,
|
|
NULL);
|
|
static DEVICE_ATTR(capability, S_IRUGO, disk_capability_show, NULL);
|
|
static DEVICE_ATTR(stat, S_IRUGO, part_stat_show, NULL);
|
|
static DEVICE_ATTR(inflight, S_IRUGO, part_inflight_show, NULL);
|
|
#ifdef CONFIG_FAIL_MAKE_REQUEST
|
|
static struct device_attribute dev_attr_fail =
|
|
__ATTR(make-it-fail, S_IRUGO|S_IWUSR, part_fail_show, part_fail_store);
|
|
#endif
|
|
#ifdef CONFIG_FAIL_IO_TIMEOUT
|
|
static struct device_attribute dev_attr_fail_timeout =
|
|
__ATTR(io-timeout-fail, S_IRUGO|S_IWUSR, 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_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,
|
|
#ifdef CONFIG_FAIL_MAKE_REQUEST
|
|
&dev_attr_fail.attr,
|
|
#endif
|
|
#ifdef CONFIG_FAIL_IO_TIMEOUT
|
|
&dev_attr_fail_timeout.attr,
|
|
#endif
|
|
NULL
|
|
};
|
|
|
|
static struct attribute_group disk_attr_group = {
|
|
.attrs = disk_attrs,
|
|
};
|
|
|
|
static const struct attribute_group *disk_attr_groups[] = {
|
|
&disk_attr_group,
|
|
NULL
|
|
};
|
|
|
|
/**
|
|
* disk_replace_part_tbl - replace disk->part_tbl in RCU-safe way
|
|
* @disk: disk to replace part_tbl for
|
|
* @new_ptbl: new part_tbl to install
|
|
*
|
|
* Replace disk->part_tbl with @new_ptbl in RCU-safe way. The
|
|
* original ptbl is freed using RCU callback.
|
|
*
|
|
* LOCKING:
|
|
* Matching bd_mutx locked.
|
|
*/
|
|
static void disk_replace_part_tbl(struct gendisk *disk,
|
|
struct disk_part_tbl *new_ptbl)
|
|
{
|
|
struct disk_part_tbl *old_ptbl = disk->part_tbl;
|
|
|
|
rcu_assign_pointer(disk->part_tbl, new_ptbl);
|
|
|
|
if (old_ptbl) {
|
|
rcu_assign_pointer(old_ptbl->last_lookup, NULL);
|
|
kfree_rcu(old_ptbl, rcu_head);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* disk_expand_part_tbl - expand disk->part_tbl
|
|
* @disk: disk to expand part_tbl for
|
|
* @partno: expand such that this partno can fit in
|
|
*
|
|
* Expand disk->part_tbl such that @partno can fit in. disk->part_tbl
|
|
* uses RCU to allow unlocked dereferencing for stats and other stuff.
|
|
*
|
|
* LOCKING:
|
|
* Matching bd_mutex locked, might sleep.
|
|
*
|
|
* RETURNS:
|
|
* 0 on success, -errno on failure.
|
|
*/
|
|
int disk_expand_part_tbl(struct gendisk *disk, int partno)
|
|
{
|
|
struct disk_part_tbl *old_ptbl = disk->part_tbl;
|
|
struct disk_part_tbl *new_ptbl;
|
|
int len = old_ptbl ? old_ptbl->len : 0;
|
|
int i, target;
|
|
size_t size;
|
|
|
|
/*
|
|
* check for int overflow, since we can get here from blkpg_ioctl()
|
|
* with a user passed 'partno'.
|
|
*/
|
|
target = partno + 1;
|
|
if (target < 0)
|
|
return -EINVAL;
|
|
|
|
/* disk_max_parts() is zero during initialization, ignore if so */
|
|
if (disk_max_parts(disk) && target > disk_max_parts(disk))
|
|
return -EINVAL;
|
|
|
|
if (target <= len)
|
|
return 0;
|
|
|
|
size = sizeof(*new_ptbl) + target * sizeof(new_ptbl->part[0]);
|
|
new_ptbl = kzalloc_node(size, GFP_KERNEL, disk->node_id);
|
|
if (!new_ptbl)
|
|
return -ENOMEM;
|
|
|
|
new_ptbl->len = target;
|
|
|
|
for (i = 0; i < len; i++)
|
|
rcu_assign_pointer(new_ptbl->part[i], old_ptbl->part[i]);
|
|
|
|
disk_replace_part_tbl(disk, new_ptbl);
|
|
return 0;
|
|
}
|
|
|
|
static void disk_release(struct device *dev)
|
|
{
|
|
struct gendisk *disk = dev_to_disk(dev);
|
|
|
|
blk_free_devt(dev->devt);
|
|
disk_release_events(disk);
|
|
kfree(disk->random);
|
|
disk_replace_part_tbl(disk, NULL);
|
|
hd_free_part(&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->devnode)
|
|
return disk->devnode(disk, mode);
|
|
return NULL;
|
|
}
|
|
|
|
static 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 hd_struct *hd;
|
|
char buf[BDEVNAME_SIZE];
|
|
int cpu;
|
|
|
|
/*
|
|
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))) {
|
|
cpu = part_stat_lock();
|
|
part_round_stats(cpu, hd);
|
|
part_stat_unlock();
|
|
seq_printf(seqf, "%4d %7d %s %lu %lu %lu "
|
|
"%u %lu %lu %lu %u %u %u %u\n",
|
|
MAJOR(part_devt(hd)), MINOR(part_devt(hd)),
|
|
disk_name(gp, hd->partno, buf),
|
|
part_stat_read(hd, ios[READ]),
|
|
part_stat_read(hd, merges[READ]),
|
|
part_stat_read(hd, sectors[READ]),
|
|
jiffies_to_msecs(part_stat_read(hd, ticks[READ])),
|
|
part_stat_read(hd, ios[WRITE]),
|
|
part_stat_read(hd, merges[WRITE]),
|
|
part_stat_read(hd, sectors[WRITE]),
|
|
jiffies_to_msecs(part_stat_read(hd, ticks[WRITE])),
|
|
part_in_flight(hd),
|
|
jiffies_to_msecs(part_stat_read(hd, io_ticks)),
|
|
jiffies_to_msecs(part_stat_read(hd, time_in_queue))
|
|
);
|
|
}
|
|
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 diskstats_open(struct inode *inode, struct file *file)
|
|
{
|
|
return seq_open(file, &diskstats_op);
|
|
}
|
|
|
|
static const struct file_operations proc_diskstats_operations = {
|
|
.open = diskstats_open,
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = seq_release,
|
|
};
|
|
|
|
static int __init proc_genhd_init(void)
|
|
{
|
|
proc_create("diskstats", 0, NULL, &proc_diskstats_operations);
|
|
proc_create("partitions", 0, NULL, &proc_partitions_operations);
|
|
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 hd_struct *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 = disk_get_part(disk, partno);
|
|
if (part) {
|
|
devt = part_devt(part);
|
|
disk_put_part(part);
|
|
break;
|
|
}
|
|
disk_put_part(part);
|
|
}
|
|
class_dev_iter_exit(&iter);
|
|
return devt;
|
|
}
|
|
EXPORT_SYMBOL(blk_lookup_devt);
|
|
|
|
struct gendisk *alloc_disk(int minors)
|
|
{
|
|
return alloc_disk_node(minors, NUMA_NO_NODE);
|
|
}
|
|
EXPORT_SYMBOL(alloc_disk);
|
|
|
|
struct gendisk *alloc_disk_node(int minors, int node_id)
|
|
{
|
|
struct gendisk *disk;
|
|
|
|
disk = kzalloc_node(sizeof(struct gendisk), GFP_KERNEL, node_id);
|
|
if (disk) {
|
|
if (!init_part_stats(&disk->part0)) {
|
|
kfree(disk);
|
|
return NULL;
|
|
}
|
|
disk->node_id = node_id;
|
|
if (disk_expand_part_tbl(disk, 0)) {
|
|
free_part_stats(&disk->part0);
|
|
kfree(disk);
|
|
return NULL;
|
|
}
|
|
disk->part_tbl->part[0] = &disk->part0;
|
|
|
|
/*
|
|
* set_capacity() and get_capacity() currently don't use
|
|
* seqcounter to read/update the part0->nr_sects. Still init
|
|
* the counter as we can read the sectors in IO submission
|
|
* patch using seqence counters.
|
|
*
|
|
* TODO: Ideally set_capacity() and get_capacity() should be
|
|
* converted to make use of bd_mutex and sequence counters.
|
|
*/
|
|
seqcount_init(&disk->part0.nr_sects_seq);
|
|
if (hd_ref_init(&disk->part0)) {
|
|
hd_free_part(&disk->part0);
|
|
kfree(disk);
|
|
return NULL;
|
|
}
|
|
|
|
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;
|
|
}
|
|
EXPORT_SYMBOL(alloc_disk_node);
|
|
|
|
struct kobject *get_disk(struct gendisk *disk)
|
|
{
|
|
struct module *owner;
|
|
struct kobject *kobj;
|
|
|
|
if (!disk->fops)
|
|
return NULL;
|
|
owner = disk->fops->owner;
|
|
if (owner && !try_module_get(owner))
|
|
return NULL;
|
|
kobj = kobject_get(&disk_to_dev(disk)->kobj);
|
|
if (kobj == NULL) {
|
|
module_put(owner);
|
|
return NULL;
|
|
}
|
|
return kobj;
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL(get_disk);
|
|
|
|
void put_disk(struct gendisk *disk)
|
|
{
|
|
if (disk)
|
|
kobject_put(&disk_to_dev(disk)->kobj);
|
|
}
|
|
|
|
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);
|
|
}
|
|
|
|
void set_device_ro(struct block_device *bdev, int flag)
|
|
{
|
|
bdev->bd_part->policy = flag;
|
|
}
|
|
|
|
EXPORT_SYMBOL(set_device_ro);
|
|
|
|
void set_disk_ro(struct gendisk *disk, int flag)
|
|
{
|
|
struct disk_part_iter piter;
|
|
struct hd_struct *part;
|
|
|
|
if (disk->part0.policy != flag) {
|
|
set_disk_ro_uevent(disk, flag);
|
|
disk->part0.policy = flag;
|
|
}
|
|
|
|
disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY);
|
|
while ((part = disk_part_iter_next(&piter)))
|
|
part->policy = flag;
|
|
disk_part_iter_exit(&piter);
|
|
}
|
|
|
|
EXPORT_SYMBOL(set_disk_ro);
|
|
|
|
int bdev_read_only(struct block_device *bdev)
|
|
{
|
|
if (!bdev)
|
|
return 0;
|
|
return bdev->bd_part->policy;
|
|
}
|
|
|
|
EXPORT_SYMBOL(bdev_read_only);
|
|
|
|
int invalidate_partition(struct gendisk *disk, int partno)
|
|
{
|
|
int res = 0;
|
|
struct block_device *bdev = bdget_disk(disk, partno);
|
|
if (bdev) {
|
|
fsync_bdev(bdev);
|
|
res = __invalidate_device(bdev, true);
|
|
bdput(bdev);
|
|
}
|
|
return res;
|
|
}
|
|
|
|
EXPORT_SYMBOL(invalidate_partition);
|
|
|
|
/*
|
|
* 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 iff there are events which
|
|
* can't be monitored asynchronously.
|
|
*/
|
|
if (ev->poll_msecs >= 0)
|
|
intv_msecs = ev->poll_msecs;
|
|
else if (disk->events & ~disk->async_events)
|
|
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;
|
|
|
|
/*
|
|
* Not exactly a latency critical operation, set poll timer
|
|
* slack to 25% and kick event check.
|
|
*/
|
|
intv = disk_events_poll_jiffies(disk);
|
|
set_timer_slack(&ev->dwork.timer, intv / 4);
|
|
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.
|
|
*/
|
|
unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask)
|
|
{
|
|
const struct block_device_operations *bdops = disk->fops;
|
|
struct disk_events *ev = disk->ev;
|
|
unsigned int pending;
|
|
unsigned int clearing = mask;
|
|
|
|
if (!ev) {
|
|
/* for drivers still using the old ->media_changed method */
|
|
if ((mask & DISK_EVENT_MEDIA_CHANGE) &&
|
|
bdops->media_changed && bdops->media_changed(disk))
|
|
return DISK_EVENT_MEDIA_CHANGE;
|
|
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;
|
|
}
|
|
|
|
/*
|
|
* 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. Unlisted events are processed the
|
|
* same internally but never get reported to userland.
|
|
*/
|
|
for (i = 0; i < ARRAY_SIZE(disk_uevents); i++)
|
|
if (events & disk->events & (1 << i))
|
|
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
|
|
* 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);
|
|
|
|
return __disk_events_show(disk->events, buf);
|
|
}
|
|
|
|
static ssize_t disk_events_async_show(struct device *dev,
|
|
struct device_attribute *attr, char *buf)
|
|
{
|
|
struct gendisk *disk = dev_to_disk(dev);
|
|
|
|
return __disk_events_show(disk->async_events, buf);
|
|
}
|
|
|
|
static ssize_t disk_events_poll_msecs_show(struct device *dev,
|
|
struct device_attribute *attr,
|
|
char *buf)
|
|
{
|
|
struct gendisk *disk = dev_to_disk(dev);
|
|
|
|
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;
|
|
|
|
disk_block_events(disk);
|
|
disk->ev->poll_msecs = intv;
|
|
__disk_unblock_events(disk, true);
|
|
|
|
return count;
|
|
}
|
|
|
|
static const DEVICE_ATTR(events, S_IRUGO, disk_events_show, NULL);
|
|
static const DEVICE_ATTR(events_async, S_IRUGO, disk_events_async_show, NULL);
|
|
static const DEVICE_ATTR(events_poll_msecs, S_IRUGO|S_IWUSR,
|
|
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/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)
|
|
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)
|
|
{
|
|
if (!disk->ev)
|
|
return;
|
|
|
|
/* 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);
|
|
|
|
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)
|
|
return;
|
|
|
|
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);
|
|
}
|