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 10/19] brd: use __register_blkdev to allocate devices on demand
Date: Thu, 3 Sep 2020 10:01:10 +0200 [thread overview]
Message-ID: <20200903080119.441674-11-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/brd.c | 39 +++++++++++----------------------------
1 file changed, 11 insertions(+), 28 deletions(-)
diff --git a/drivers/block/brd.c b/drivers/block/brd.c
index 2723a70eb85593..c8ac36351115ef 100644
--- a/drivers/block/brd.c
+++ b/drivers/block/brd.c
@@ -427,14 +427,15 @@ static void brd_free(struct brd_device *brd)
kfree(brd);
}
-static struct brd_device *brd_init_one(int i, bool *new)
+static void brd_probe(dev_t dev)
{
struct brd_device *brd;
+ int i = MINOR(dev) / max_part;
- *new = false;
+ mutex_lock(&brd_devices_mutex);
list_for_each_entry(brd, &brd_devices, brd_list) {
if (brd->brd_number == i)
- goto out;
+ goto out_unlock;
}
brd = brd_alloc(i);
@@ -443,9 +444,9 @@ static struct brd_device *brd_init_one(int i, bool *new)
add_disk(brd->brd_disk);
list_add_tail(&brd->brd_list, &brd_devices);
}
- *new = true;
-out:
- return brd;
+
+out_unlock:
+ mutex_unlock(&brd_devices_mutex);
}
static void brd_del_one(struct brd_device *brd)
@@ -455,23 +456,6 @@ static void brd_del_one(struct brd_device *brd)
brd_free(brd);
}
-static struct kobject *brd_probe(dev_t dev, int *part, void *data)
-{
- struct brd_device *brd;
- struct kobject *kobj;
- bool new;
-
- mutex_lock(&brd_devices_mutex);
- brd = brd_init_one(MINOR(dev) / max_part, &new);
- kobj = brd ? get_disk_and_module(brd->brd_disk) : NULL;
- mutex_unlock(&brd_devices_mutex);
-
- if (new)
- *part = 0;
-
- return kobj;
-}
-
static inline void brd_check_and_reset_par(void)
{
if (unlikely(!max_part))
@@ -511,11 +495,12 @@ static int __init brd_init(void)
* dynamically.
*/
- if (register_blkdev(RAMDISK_MAJOR, "ramdisk"))
+ if (__register_blkdev(RAMDISK_MAJOR, "ramdisk", brd_probe))
return -EIO;
brd_check_and_reset_par();
+ mutex_lock(&brd_devices_mutex);
for (i = 0; i < rd_nr; i++) {
brd = brd_alloc(i);
if (!brd)
@@ -533,9 +518,7 @@ static int __init brd_init(void)
brd->brd_disk->queue = brd->brd_queue;
add_disk(brd->brd_disk);
}
-
- blk_register_region(MKDEV(RAMDISK_MAJOR, 0), 1UL << MINORBITS,
- THIS_MODULE, brd_probe, NULL, NULL);
+ mutex_unlock(&brd_devices_mutex);
pr_info("brd: module loaded\n");
return 0;
@@ -545,6 +528,7 @@ static int __init brd_init(void)
list_del(&brd->brd_list);
brd_free(brd);
}
+ mutex_unlock(&brd_devices_mutex);
unregister_blkdev(RAMDISK_MAJOR, "ramdisk");
pr_info("brd: module NOT loaded !!!\n");
@@ -558,7 +542,6 @@ static void __exit brd_exit(void)
list_for_each_entry_safe(brd, next, &brd_devices, brd_list)
brd_del_one(brd);
- blk_unregister_region(MKDEV(RAMDISK_MAJOR, 0), 1UL << MINORBITS);
unregister_blkdev(RAMDISK_MAJOR, "ramdisk");
pr_info("brd: module unloaded\n");
--
2.28.0
next prev parent reply other threads:[~2020-09-03 8:02 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 ` Christoph Hellwig [this message]
2020-09-04 10:23 ` [PATCH 10/19] brd: use __register_blkdev to allocate devices on demand Hannes Reinecke
2020-09-03 8:01 ` [PATCH 11/19] loop: " Christoph Hellwig
2020-09-04 10:24 ` 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 10/19] brd: 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 10/19] brd: use __register_blkdev to allocate devices on demand Christoph Hellwig
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