Messages in this thread Patch in this message | | | Subject | [-mm PATCH] register_memory/unregister_memory clean ups | From | Badari Pulavarty <> | Date | Mon, 11 Feb 2008 09:23:18 -0800 |
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Hi Andrew,
While testing hotplug memory remove against -mm, I noticed that unregister_memory() is not cleaning up /sysfs entries correctly. It also de-references structures after destroying them (luckily in the code which never gets used). So, I cleaned up the code and fixed the extra reference issue.
Could you please include it in -mm ?
Thanks, Badari
register_memory()/unregister_memory() never gets called with "root". unregister_memory() is accessing kobject_name of the object just freed up. Since no one uses the code, lets take the code out. And also, make register_memory() static.
Another bug fix - before calling unregister_memory() remove_memory_block() gets a ref on kobject. unregister_memory() need to drop that ref before calling sysdev_unregister().
Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com> --- drivers/base/memory.c | 22 +++++++--------------- 1 file changed, 7 insertions(+), 15 deletions(-)
Index: linux-2.6.24/drivers/base/memory.c =================================================================== --- linux-2.6.24.orig/drivers/base/memory.c 2008-02-07 16:59:52.000000000 -0800 +++ linux-2.6.24/drivers/base/memory.c 2008-02-08 15:54:45.000000000 -0800 @@ -62,8 +62,8 @@ void unregister_memory_notifier(struct n /* * register_memory - Setup a sysfs device for a memory block */ -int register_memory(struct memory_block *memory, struct mem_section *section, - struct node *root) +static +int register_memory(struct memory_block *memory, struct mem_section *section) { int error; @@ -71,26 +71,18 @@ int register_memory(struct memory_block memory->sysdev.id = __section_nr(section); error = sysdev_register(&memory->sysdev); - - if (root && !error) - error = sysfs_create_link(&root->sysdev.kobj, - &memory->sysdev.kobj, - kobject_name(&memory->sysdev.kobj)); - return error; } static void -unregister_memory(struct memory_block *memory, struct mem_section *section, - struct node *root) +unregister_memory(struct memory_block *memory, struct mem_section *section) { BUG_ON(memory->sysdev.cls != &memory_sysdev_class); BUG_ON(memory->sysdev.id != __section_nr(section)); + /* drop the ref. we got in remove_memory_block() */ + kobject_put(&memory->sysdev.kobj); sysdev_unregister(&memory->sysdev); - if (root) - sysfs_remove_link(&root->sysdev.kobj, - kobject_name(&memory->sysdev.kobj)); } /* @@ -361,7 +353,7 @@ static int add_memory_block(unsigned lon mutex_init(&mem->state_mutex); mem->phys_device = phys_device; - ret = register_memory(mem, section, NULL); + ret = register_memory(mem, section); if (!ret) ret = mem_create_simple_file(mem, phys_index); if (!ret) @@ -415,7 +407,7 @@ int remove_memory_block(unsigned long no mem_remove_simple_file(mem, state); mem_remove_simple_file(mem, phys_device); mem_remove_simple_file(mem, removable); - unregister_memory(mem, section, NULL); + unregister_memory(mem, section); return 0; }
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