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See http://www.infradead.org/rpr.html X-Mimecast-Impersonation-Protect: Policy=CLT - Impersonation Protection Definition; Similar Internal Domain=false; Similar Monitored External Domain=false; Custom External Domain=false; Mimecast External Domain=false; Newly Observed Domain=false; Internal User Name=false; Custom Display Name List=false; Reply-to Address Mismatch=false; Targeted Threat Dictionary=false; Mimecast Threat Dictionary=false; Custom Threat Dictionary=false X-Scanned-By: MIMEDefang 2.79 on 10.11.54.5 X-loop: dm-devel@redhat.com Cc: Justin Sanders , Mike Snitzer , "Michael S. Tsirkin" , Jason Wang , linux-nvme@lists.infradead.org, Song Liu , dm-devel@redhat.com, linux-scsi@vger.kernel.org, xen-devel@lists.xenproject.org, Ilya Dryomov , Jack Wang , Konrad Rzeszutek Wilk , Josef Bacik , nbd@other.debian.org, linux-raid@vger.kernel.org, Stefan Hajnoczi , drbd-dev@tron.linbit.com, ceph-devel@vger.kernel.org, linux-block@vger.kernel.org, "Martin K. Petersen" , Minchan Kim , linux-fsdevel@vger.kernel.org, Paolo Bonzini , =?UTF-8?q?Roger=20Pau=20Monn=C3=A9?= Subject: [dm-devel] [PATCH 44/78] loop: use __register_blkdev to allocate devices on demand X-BeenThere: dm-devel@redhat.com X-Mailman-Version: 2.1.12 Precedence: junk List-Id: device-mapper development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dm-devel-bounces@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Use the simpler mechanism attached to major_name to allocate a brd device when a currently unregistered minor is accessed. Signed-off-by: Christoph Hellwig Reviewed-by: Hannes Reinecke --- drivers/block/loop.c | 30 ++++++++---------------------- 1 file changed, 8 insertions(+), 22 deletions(-) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 41caf799df721f..9a27d4f1c08aac 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -2231,24 +2231,18 @@ static int loop_lookup(struct loop_device **l, int i) return ret; } -static struct kobject *loop_probe(dev_t dev, int *part, void *data) +static void loop_probe(dev_t dev) { + int idx = MINOR(dev) >> part_shift; struct loop_device *lo; - struct kobject *kobj; - int err; + + if (max_loop && idx >= max_loop) + return; mutex_lock(&loop_ctl_mutex); - err = loop_lookup(&lo, MINOR(dev) >> part_shift); - if (err < 0) - err = loop_add(&lo, MINOR(dev) >> part_shift); - if (err < 0) - kobj = NULL; - else - kobj = get_disk_and_module(lo->lo_disk); + if (loop_lookup(&lo, idx) < 0) + loop_add(&lo, idx); mutex_unlock(&loop_ctl_mutex); - - *part = 0; - return kobj; } static long loop_control_ioctl(struct file *file, unsigned int cmd, @@ -2368,14 +2362,11 @@ static int __init loop_init(void) goto err_out; - if (register_blkdev(LOOP_MAJOR, "loop")) { + if (__register_blkdev(LOOP_MAJOR, "loop", loop_probe)) { err = -EIO; goto misc_out; } - blk_register_region(MKDEV(LOOP_MAJOR, 0), range, - THIS_MODULE, loop_probe, NULL, NULL); - /* pre-create number of devices given by config or max_loop */ mutex_lock(&loop_ctl_mutex); for (i = 0; i < nr; i++) @@ -2401,16 +2392,11 @@ static int loop_exit_cb(int id, void *ptr, void *data) static void __exit loop_exit(void) { - unsigned long range; - - range = max_loop ? max_loop << part_shift : 1UL << MINORBITS; - mutex_lock(&loop_ctl_mutex); idr_for_each(&loop_index_idr, &loop_exit_cb, NULL); idr_destroy(&loop_index_idr); - blk_unregister_region(MKDEV(LOOP_MAJOR, 0), range); unregister_blkdev(LOOP_MAJOR, "loop"); misc_deregister(&loop_misc); -- 2.29.2 -- dm-devel mailing list dm-devel@redhat.com https://www.redhat.com/mailman/listinfo/dm-devel