From: Christoph Hellwig <hch@lst.de>
To: Jens Axboe <axboe@kernel.dk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
"Rafael J. Wysocki" <rafael@kernel.org>,
Denis Efremov <efremov@linux.com>,
"David S. Miller" <davem@davemloft.net>,
Song Liu <song@kernel.org>, Al Viro <viro@zeniv.linux.org.uk>,
Finn Thain <fthain@telegraphics.com.au>,
Michael Schmitz <schmitzmic@gmail.com>,
linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-ide@vger.kernel.org, linux-raid@vger.kernel.org,
linux-scsi@vger.kernel.org, linux-m68k@lists.linux-m68k.org
Subject: [PATCH 11/19] loop: use __register_blkdev to allocate devices on demand
Date: Thu, 3 Sep 2020 10:01:11 +0200 [thread overview]
Message-ID: <20200903080119.441674-12-hch@lst.de> (raw)
In-Reply-To: <20200903080119.441674-1-hch@lst.de>
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 <hch@lst.de>
---
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 cb1191d6e945f2..15b5a0ea7cc4a9 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -2234,24 +2234,18 @@ 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,
@@ -2371,14 +2365,11 @@ 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++)
@@ -2404,16 +2395,11 @@ 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);
--
2.28.0
next prev parent reply other threads:[~2020-09-03 8:14 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-03 8:01 simplify gendisk lookup and remove struct block_device aliases v3 Christoph Hellwig
2020-09-03 8:01 ` [PATCH 01/19] char_dev: replace cdev_map with an xarray Christoph Hellwig
2020-09-04 10:16 ` Hannes Reinecke
2020-09-03 8:01 ` [PATCH 02/19] block: merge drivers/base/map.c into block/genhd.c Christoph Hellwig
2020-09-04 10:17 ` Hannes Reinecke
2020-09-03 8:01 ` [PATCH 03/19] block: cleanup del_gendisk a bit Christoph Hellwig
2020-09-04 10:18 ` Hannes Reinecke
2020-09-03 8:01 ` [PATCH 04/19] block: split block_class_lock Christoph Hellwig
2020-09-04 10:19 ` Hannes Reinecke
2020-09-03 8:01 ` [PATCH 05/19] block: rework requesting modules for unclaimed devices Christoph Hellwig
2020-09-04 10:20 ` Hannes Reinecke
2020-09-03 8:01 ` [PATCH 06/19] block: add an optional probe callback to major_names Christoph Hellwig
2020-09-04 10:20 ` Hannes Reinecke
2020-09-03 8:01 ` [PATCH 07/19] ide: remove ide_{,un}register_region Christoph Hellwig
2020-09-03 8:01 ` [PATCH 08/19] swim: don't call blk_register_region Christoph Hellwig
2020-09-04 10:21 ` Hannes Reinecke
2020-09-03 8:01 ` [PATCH 09/19] sd: use __register_blkdev to avoid a modprobe for an unregistered dev_t Christoph Hellwig
2020-09-04 10:22 ` Hannes Reinecke
2020-09-03 8:01 ` [PATCH 10/19] brd: use __register_blkdev to allocate devices on demand Christoph Hellwig
2020-09-04 10:23 ` Hannes Reinecke
2020-09-03 8:01 ` Christoph Hellwig [this message]
2020-09-04 10:24 ` [PATCH 11/19] loop: " Hannes Reinecke
2020-09-03 8:01 ` [PATCH 12/19] md: " Christoph Hellwig
2020-09-04 10:25 ` Hannes Reinecke
2020-09-03 8:01 ` [PATCH 13/19] ide: switch to __register_blkdev for command set probing Christoph Hellwig
2020-09-04 10:26 ` Hannes Reinecke
2020-09-03 8:01 ` [PATCH 14/19] floppy: use a separate gendisk for each media format Christoph Hellwig
2020-09-04 9:59 ` Denis Efremov
2020-09-04 10:28 ` Hannes Reinecke
2020-09-03 8:01 ` [PATCH 15/19] amiflop: use separate gendisks for Amiga vs MS-DOS mode Christoph Hellwig
2020-09-04 10:28 ` Hannes Reinecke
2020-09-03 8:01 ` [PATCH 16/19] ataflop: use a separate gendisk for each media format Christoph Hellwig
2020-09-03 8:14 ` John Paul Adrian Glaubitz
2020-09-04 10:29 ` Hannes Reinecke
2020-09-03 8:01 ` [PATCH 17/19] z2ram: reindent Christoph Hellwig
2020-09-04 10:29 ` Hannes Reinecke
2020-09-03 8:01 ` [PATCH 18/19] z2ram: use separate gendisk for the different modes Christoph Hellwig
2020-09-04 10:30 ` Hannes Reinecke
2020-09-03 8:01 ` [PATCH 19/19] block: switch gendisk lookup to a simple xarray Christoph Hellwig
2020-09-04 10:30 ` Hannes Reinecke
-- strict thread matches above, loose matches on Subject: below --
2020-08-30 6:24 simplify gendisk lookup and remove struct block_device aliases v2 Christoph Hellwig
2020-08-30 6:24 ` [PATCH 11/19] loop: use __register_blkdev to allocate devices on demand Christoph Hellwig
2020-08-26 6:24 simplify gendisk lookup and remove struct block_device aliases Christoph Hellwig
2020-08-26 6:24 ` [PATCH 11/19] loop: use __register_blkdev to allocate devices on demand Christoph Hellwig
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