lkml.org 
[lkml]   [2002]   [Nov]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
SubjectRe: Patch?: 2.5.46/drivers/block/genhd.c - static allocation of gendisks
	Sorry pelting you with duplicate patches.  Here is yet
another version of my init_disk() patch.

I changed init_disk to take the disk partitions pointer
as a parameter to make it hard for users of this interface to
forget to set it.

Also, I replaced disk.destructor() with disk.kfree_arg,
to avoid having to write a bunch of destructors that look like this:

void foo_destructor(struct gendisk *disk)
{
struct foo_private *foo_priv =
container_of(disk, struct foo_private, mygendisk);
kfree(foo_priv);
}

foo's hardware removal function would call put_disk,
and the disk's destructor would be called when the disk's reference
count dropped to zero. However, I'd rather not have to write
a bunch of duplicative destructor functions and I think they
all would just call kfree.

By the way, I believe that the example of the IDE changes that
I posted does not currently have this issue because the gendisks are in
the static hwifs[] array, which is not deallocated until the module is
unloaded, and the module is protected by a reference count.

--
Adam J. Richter __ ______________ 575 Oroville Road
adam@yggdrasil.com \ / Milpitas, California 95035
+1 408 309-6081 | g g d r a s i l United States of America
"Free Software For The Rest Of Us."
--- linux-2.5.46/include/linux/genhd.h 2002-11-04 14:30:08.000000000 -0800
+++ linux/include/linux/genhd.h 2002-11-06 06:56:41.000000000 -0800
@@ -107,6 +108,7 @@
int in_flight;
unsigned long stamp, stamp_idle;
unsigned time_in_queue;
+ void *kfree_arg;
};

/* drivers/block/ll_rw_blk.c */
@@ -283,8 +285,10 @@
extern void add_partition(struct gendisk *, int, sector_t, sector_t);
extern void delete_partition(struct gendisk *, int);

+extern void init_disk(struct gendisk *disk, int minors,
+ struct hd_struct *partitions);
extern struct gendisk *alloc_disk(int minors);
extern struct gendisk *get_disk(struct gendisk *disk);
extern void put_disk(struct gendisk *disk);
--- linux-2.5.46/drivers/block/genhd.c 2002-11-04 14:30:27.000000000 -0800
+++ linux/drivers/block/genhd.c 2002-11-06 06:58:53.000000000 -0800
@@ -373,8 +370,7 @@
{
struct gendisk *disk = to_disk(kobj);
kfree(disk->random);
- kfree(disk->part);
- kfree(disk);
+ kfree(disk->kfree_arg);
}

struct subsystem block_subsys = {
@@ -384,28 +380,33 @@
.default_attrs = default_attrs,
};

+/* init_disk assumes disk should is initialized to all zeroes,
+ except for disk->part, which points to the partitions structures,
+ which are also assumed to be initialized to all zeroes. */
+void init_disk(struct gendisk *disk, int minors, struct hd_struct *parts)
+{
+ BUG_ON(minors > 1 && parts == NULL);
+
+ disk->minors = minors;
+ disk->part = parts;
+ while (minors >>= 1)
+ disk->minor_shift++;
+ kobject_init(&disk->kobj);
+ disk->kobj.subsys = &block_subsys;
+ INIT_LIST_HEAD(&disk->full_list);
+ rand_initialize_disk(disk);
+}
+
struct gendisk *alloc_disk(int minors)
{
- struct gendisk *disk = kmalloc(sizeof(struct gendisk), GFP_KERNEL);
+ int size = sizeof(struct gendisk) +
+ (minors - 1) * sizeof(struct hd_struct);
+ struct gendisk *disk = kmalloc(size, GFP_KERNEL);
if (disk) {
- memset(disk, 0, sizeof(struct gendisk));
- if (minors > 1) {
- int size = (minors - 1) * sizeof(struct hd_struct);
- disk->part = kmalloc(size, GFP_KERNEL);
- if (!disk->part) {
- kfree(disk);
- return NULL;
- }
- memset(disk->part, 0, size);
- }
- disk->minors = minors;
- while (minors >>= 1)
- disk->minor_shift++;
- kobject_init(&disk->kobj);
- disk->kobj.subsys = &block_subsys;
- INIT_LIST_HEAD(&disk->full_list);
+ memset(disk, 0, size);
+ init_disk(disk, minors, (struct hd_struct*) &disk[1]);
+ disk->kfree_arg = disk;
}
- rand_initialize_disk(disk);
return disk;
}

@@ -426,6 +427,7 @@
kobject_put(&disk->kobj);
}

+EXPORT_SYMBOL(init_disk);
EXPORT_SYMBOL(alloc_disk);
EXPORT_SYMBOL(get_disk);
EXPORT_SYMBOL(put_disk);
\
 
 \ /
  Last update: 2005-03-22 13:30    [W:0.077 / U:0.696 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site