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block: remove DISK_PITER_REVERSE

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There is good reason to iterate backwards when deleting all partitions in
del_gendisk, just like we don't in blk_drop_partitions.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Christoph Hellwig 2021-01-24 11:02:40 +01:00 committed by Jens Axboe
parent bc359d03c7
commit 0470dd9d5f
2 changed files with 7 additions and 31 deletions
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37
block/genhd.c
View File

@ -184,24 +184,13 @@ static struct block_device *__disk_get_part(struct gendisk *disk, int partno)
void disk_part_iter_init(struct disk_part_iter *piter, struct gendisk *disk,
unsigned int flags)
{
struct disk_part_tbl *ptbl;
rcu_read_lock();
ptbl = rcu_dereference(disk->part_tbl);
piter->disk = disk;
piter->part = NULL;
if (flags & DISK_PITER_REVERSE)
piter->idx = ptbl->len - 1;
else if (flags & (DISK_PITER_INCL_PART0 | DISK_PITER_INCL_EMPTY_PART0))
if (flags & (DISK_PITER_INCL_PART0 | DISK_PITER_INCL_EMPTY_PART0))
piter->idx = 0;
else
piter->idx = 1;
piter->flags = flags;
rcu_read_unlock();
}
/**
@ -216,7 +205,6 @@ void disk_part_iter_init(struct disk_part_iter *piter, struct gendisk *disk,
struct block_device *disk_part_iter_next(struct disk_part_iter *piter)
{
struct disk_part_tbl *ptbl;
int inc, end;
/* put the last partition */
disk_part_iter_exit(piter);
@ -225,21 +213,8 @@ struct block_device *disk_part_iter_next(struct disk_part_iter *piter)
rcu_read_lock();
ptbl = rcu_dereference(piter->disk->part_tbl);
/* determine iteration parameters */
if (piter->flags & DISK_PITER_REVERSE) {
inc = -1;
if (piter->flags & (DISK_PITER_INCL_PART0 |
DISK_PITER_INCL_EMPTY_PART0))
end = -1;
else
end = 0;
} else {
inc = 1;
end = ptbl->len;
}
/* iterate to the next partition */
for (; piter->idx != end; piter->idx += inc) {
for (; piter->idx != ptbl->len; piter->idx += 1) {
struct block_device *part;
part = rcu_dereference(ptbl->part[piter->idx]);
@ -257,7 +232,10 @@ struct block_device *disk_part_iter_next(struct disk_part_iter *piter)
continue;
}
piter->idx += inc;
piter->part = bdgrab(part);
if (!piter->part)
continue;
piter->idx += 1;
break;
}
@ -781,8 +759,7 @@ void del_gendisk(struct gendisk *disk)
down_write(&bdev_lookup_sem);
/* invalidate stuff */
disk_part_iter_init(&piter, disk,
DISK_PITER_INCL_EMPTY | DISK_PITER_REVERSE);
disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY);
while ((part = disk_part_iter_next(&piter))) {
invalidate_partition(part);
delete_partition(part);

1
include/linux/genhd.h
View File

@ -218,7 +218,6 @@ void disk_uevent(struct gendisk *disk, enum kobject_action action);
/*
* Smarter partition iterator without context limits.
*/
#define DISK_PITER_REVERSE (1 << 0) /* iterate in the reverse direction */
#define DISK_PITER_INCL_EMPTY (1 << 1) /* include 0-sized parts */
#define DISK_PITER_INCL_PART0 (1 << 2) /* include partition 0 */
#define DISK_PITER_INCL_EMPTY_PART0 (1 << 3) /* include empty partition 0 */