Messages in this thread Patch in this message | | | Date | Wed, 6 Nov 2002 07:18:10 -0800 | From | "Adam J. Richter" <> | Subject | Re: Patch?: 2.5.46/drivers/block/genhd.c - static allocation of gendisks |
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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); | |