commit 2da78092dd upstream.
Releases the dev_t minor when all references are closed to prevent
another device from acquiring the same major/minor.
Since the partition's release may be invoked from call_rcu's soft-irq
context, the ext_dev_idr's mutex had to be replaced with a spinlock so
as not so sleep.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
[bwh: Backported to 3.2:
- Adjust filename
- idr insertion API is different, and blk_alloc_devt() is preallocating
a node in a different way]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
a288cafece