On 11/25/2015 09:57 AM, Wenwei Tao wrote:
Hi Matias
I think list_for_each_entry_safe(pos, n, head, member) cannot avoid
race condition
the item point by ‘n’ can be deleted and freed in the same time we
operate on 'pos'
so lock is still necessary.
I've made the patch like this, ok?
To avoid race conditions, traverse dev, media manager,
and target lists and also register, unregister entries
to/from them, should be always under the nvm_lock control.
Signed-off-by: Wenwei Tao <ww.tao0320@xxxxxxxxx>
Signed-off-by: Matias Bjørling <m@xxxxxxxxxxx>
---
drivers/lightnvm/core.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/lightnvm/core.c b/drivers/lightnvm/core.c
index ea6dba5..9f901f6 100644
--- a/drivers/lightnvm/core.c
+++ b/drivers/lightnvm/core.c
@@ -127,9 +127,11 @@ static struct nvm_dev *nvm_find_nvm_dev(const char
*name)
{
struct nvm_dev *dev;
+ down_write(&nvm_lock);
list_for_each_entry(dev, &nvm_devices, devices)
if (!strcmp(name, dev->name))
return dev;
+ up_write(&nvm_lock);
return NULL;
}
@@ -388,13 +390,14 @@ static int nvm_create_target(struct nvm_dev *dev,
}
}
+ down_write(&nvm_lock);
tt = nvm_find_target_type(create->tgttype);
if (!tt) {
pr_err("nvm: target type %s not found\n", create->tgttype);
+ up_write(&nvm_lock);
return -EINVAL;
}
- down_write(&nvm_lock);
list_for_each_entry(t, &dev->online_targets, list) {
if (!strcmp(create->tgtname, t->disk->disk_name)) {
pr_err("nvm: target name already exists.\n");
--
2.1.4
--
To unsubscribe from this list: send the line "unsubscribe linux-block" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
