lightnvm: prevent target type module removal when in use

If target type module e.g. pblk here is unloaded (rmmod) while module
is in use (after creating target) system crashes.  We fix this by
using module API refcnt.

Signed-off-by: Rakesh Pandit <rakesh@tuxera.com>
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Rakesh Pandit 2017-10-13 14:45:50 +02:00 committed by Jens Axboe
parent 47bc227dee
commit 900148296b
3 changed files with 6 additions and 0 deletions

View File

@ -22,6 +22,7 @@
#include <linux/types.h>
#include <linux/sem.h>
#include <linux/bitmap.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/miscdevice.h>
#include <linux/lightnvm.h>
@ -316,6 +317,8 @@ static int nvm_create_tgt(struct nvm_dev *dev, struct nvm_ioctl_create *create)
list_add_tail(&t->list, &dev->targets);
mutex_unlock(&dev->mlock);
__module_get(tt->owner);
return 0;
err_sysfs:
if (tt->exit)
@ -351,6 +354,7 @@ static void __nvm_remove_target(struct nvm_target *t)
nvm_remove_tgt_dev(t->dev, 1);
put_disk(tdisk);
module_put(t->type->owner);
list_del(&t->list);
kfree(t);

View File

@ -1044,6 +1044,7 @@ static struct nvm_tgt_type tt_pblk = {
.sysfs_init = pblk_sysfs_init,
.sysfs_exit = pblk_sysfs_exit,
.owner = THIS_MODULE,
};
static int __init pblk_module_init(void)

View File

@ -460,6 +460,7 @@ struct nvm_tgt_type {
/* For internal use */
struct list_head list;
struct module *owner;
};
extern struct nvm_tgt_type *nvm_find_target_type(const char *, int);