Re: [PATCH 11/19] loop: use __register_blkdev to allocate devices on demand
On 9/3/20 10:01 AM, Christoph Hellwig wrote: 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 --- drivers/block/loop.c | 30 -- 1 file changed, 8 insertions(+), 22 deletions(-) Reviewed-by: Hannes Reinecke Cheers, Hannes -- Dr. Hannes ReineckeKernel Storage Architect h...@suse.de +49 911 74053 688 SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg HRB 36809 (AG Nürnberg), Geschäftsführer: Felix Imendörffer
[PATCH 11/19] loop: use __register_blkdev to allocate devices on demand
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
---
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(_ctl_mutex);
- err = loop_lookup(, MINOR(dev) >> part_shift);
- if (err < 0)
- err = loop_add(, MINOR(dev) >> part_shift);
- if (err < 0)
- kobj = NULL;
- else
- kobj = get_disk_and_module(lo->lo_disk);
+ if (loop_lookup(, idx) < 0)
+ loop_add(, idx);
mutex_unlock(_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(_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(_ctl_mutex);
idr_for_each(_index_idr, _exit_cb, NULL);
idr_destroy(_index_idr);
- blk_unregister_region(MKDEV(LOOP_MAJOR, 0), range);
unregister_blkdev(LOOP_MAJOR, "loop");
misc_deregister(_misc);
--
2.28.0
[PATCH 11/19] loop: use __register_blkdev to allocate devices on demand
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
---
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 5a991510136225..7c944a425f718f 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(_ctl_mutex);
- err = loop_lookup(, MINOR(dev) >> part_shift);
- if (err < 0)
- err = loop_add(, MINOR(dev) >> part_shift);
- if (err < 0)
- kobj = NULL;
- else
- kobj = get_disk_and_module(lo->lo_disk);
+ if (loop_lookup(, idx) < 0)
+ loop_add(, idx);
mutex_unlock(_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(_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(_ctl_mutex);
idr_for_each(_index_idr, _exit_cb, NULL);
idr_destroy(_index_idr);
- blk_unregister_region(MKDEV(LOOP_MAJOR, 0), range);
unregister_blkdev(LOOP_MAJOR, "loop");
misc_deregister(_misc);
--
2.28.0
[PATCH 11/19] loop: use __register_blkdev to allocate devices on demand
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
---
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 5a991510136225..7c944a425f718f 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(_ctl_mutex);
- err = loop_lookup(, MINOR(dev) >> part_shift);
- if (err < 0)
- err = loop_add(, MINOR(dev) >> part_shift);
- if (err < 0)
- kobj = NULL;
- else
- kobj = get_disk_and_module(lo->lo_disk);
+ if (loop_lookup(, idx) < 0)
+ loop_add(, idx);
mutex_unlock(_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(_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(_ctl_mutex);
idr_for_each(_index_idr, _exit_cb, NULL);
idr_destroy(_index_idr);
- blk_unregister_region(MKDEV(LOOP_MAJOR, 0), range);
unregister_blkdev(LOOP_MAJOR, "loop");
misc_deregister(_misc);
--
2.28.0
