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Revert "loop: cleanup partitions when detaching loop device"

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This reverts commit 8761a3dc1f.

There are situations where the destruction path is called
with the bdev->bd_mutex already held, which then deadlocks in
loop_clr_fd(). The normal partition cleanup does a trylock()
on the mutex, but it'd be nice to have a more bullet proof
method in loop. So punt this more involved fix to the next
merge window, and just back out this buggy fix for now.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Jens Axboe 2013-04-08 10:12:11 +02:00
parent c66bb3f075
commit c2fccc1c9f
2 changed files with 2 additions and 20 deletions
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1
block/partition-generic.c
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@ -257,7 +257,6 @@ void delete_partition(struct gendisk *disk, int partno)
hd_struct_put(part);
}
EXPORT_SYMBOL(delete_partition);
static ssize_t whole_disk_show(struct device *dev,
struct device_attribute *attr, char *buf)

21
drivers/block/loop.c
View file

@ -1044,29 +1044,12 @@ static int loop_clr_fd(struct loop_device *lo)
lo->lo_state = Lo_unbound;
/* This is safe: open() is still holding a reference. */
module_put(THIS_MODULE);
if (lo->lo_flags & LO_FLAGS_PARTSCAN && bdev)
ioctl_by_bdev(bdev, BLKRRPART, 0);
lo->lo_flags = 0;
if (!part_shift)
lo->lo_disk->flags |= GENHD_FL_NO_PART_SCAN;
mutex_unlock(&lo->lo_ctl_mutex);
/*
* Remove all partitions, since BLKRRPART won't remove user
* added partitions when max_part=0
*/
if (bdev) {
struct disk_part_iter piter;
struct hd_struct *part;
mutex_lock_nested(&bdev->bd_mutex, 1);
invalidate_partition(bdev->bd_disk, 0);
disk_part_iter_init(&piter, bdev->bd_disk,
DISK_PITER_INCL_EMPTY);
while ((part = disk_part_iter_next(&piter)))
delete_partition(bdev->bd_disk, part->partno);
disk_part_iter_exit(&piter);
mutex_unlock(&bdev->bd_mutex);
}
/*
* Need not hold lo_ctl_mutex to fput backing file.
* Calling fput holding lo_ctl_mutex triggers a circular