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 06/19] block: add an optional probe callback to major_names
Date: Thu, 3 Sep 2020 10:01:06 +0200 [thread overview]
Message-ID: <20200903080119.441674-7-hch@lst.de> (raw)
In-Reply-To: <20200903080119.441674-1-hch@lst.de>
Add a callback to the major_names array that allows a driver to override
how to probe for dev_t that doesn't currently have a gendisk registered.
This will help separating the lookup of the gendisk by dev_t vs probe
action for a not currently registered dev_t.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
block/genhd.c | 21 ++++++++++++++++++---
include/linux/genhd.h | 5 ++++-
2 files changed, 22 insertions(+), 4 deletions(-)
diff --git a/block/genhd.c b/block/genhd.c
index d9ecc751fc956c..3abd764443a6af 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -399,6 +399,7 @@ static struct blk_major_name {
struct blk_major_name *next;
int major;
char name[16];
+ void (*probe)(dev_t devt);
} *major_names[BLKDEV_MAJOR_HASH_SIZE];
static DEFINE_MUTEX(major_names_lock);
@@ -441,7 +442,8 @@ void blkdev_show(struct seq_file *seqf, off_t offset)
* See Documentation/admin-guide/devices.txt for the list of allocated
* major numbers.
*/
-int register_blkdev(unsigned int major, const char *name)
+int __register_blkdev(unsigned int major, const char *name,
+ void (*probe)(dev_t devt))
{
struct blk_major_name **n, *p;
int index, ret = 0;
@@ -480,6 +482,7 @@ int register_blkdev(unsigned int major, const char *name)
}
p->major = major;
+ p->probe = probe;
strlcpy(p->name, name, sizeof(p->name));
p->next = NULL;
index = major_to_index(major);
@@ -502,8 +505,7 @@ int register_blkdev(unsigned int major, const char *name)
mutex_unlock(&major_names_lock);
return ret;
}
-
-EXPORT_SYMBOL(register_blkdev);
+EXPORT_SYMBOL(__register_blkdev);
void unregister_blkdev(unsigned int major, const char *name)
{
@@ -1035,6 +1037,19 @@ static ssize_t disk_badblocks_store(struct device *dev,
static void request_gendisk_module(dev_t devt)
{
+ unsigned int major = MAJOR(devt);
+ struct blk_major_name **n;
+
+ mutex_lock(&major_names_lock);
+ for (n = &major_names[major_to_index(major)]; *n; n = &(*n)->next) {
+ if ((*n)->major == major && (*n)->probe) {
+ (*n)->probe(devt);
+ mutex_unlock(&major_names_lock);
+ return;
+ }
+ }
+ mutex_unlock(&major_names_lock);
+
if (request_module("block-major-%d-%d", MAJOR(devt), MINOR(devt)) > 0)
/* Make old-style 2.4 aliases work */
request_module("block-major-%d", MAJOR(devt));
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index c618b27292fcc8..a808afe80a4fec 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -367,7 +367,10 @@ extern void blk_unregister_region(dev_t devt, unsigned long range);
#define alloc_disk(minors) alloc_disk_node(minors, NUMA_NO_NODE)
-int register_blkdev(unsigned int major, const char *name);
+int __register_blkdev(unsigned int major, const char *name,
+ void (*probe)(dev_t devt));
+#define register_blkdev(major, name) \
+ __register_blkdev(major, name, NULL)
void unregister_blkdev(unsigned int major, const char *name);
void revalidate_disk_size(struct gendisk *disk, bool verbose);
--
2.28.0
next prev parent reply other threads:[~2020-09-03 8:15 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 ` Christoph Hellwig [this message]
2020-09-04 10:20 ` [PATCH 06/19] block: add an optional probe callback to major_names 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 ` [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 06/19] block: add an optional probe callback to major_names Christoph Hellwig
2020-08-26 6:24 simplify gendisk lookup and remove struct block_device aliases Christoph Hellwig
2020-08-26 6:24 ` [PATCH 06/19] block: add an optional probe callback to major_names Christoph Hellwig
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