From: Rakesh Pandit <rakesh@tuxera.com>
Date: Fri, 13 Oct 2017 14:45:52 +0200
Subject: [PATCH] lightnvm: protect target type list with correct locks
Git-commit: 88d31ea2676696ad0802a361c8b824f0762fa34c
Patch-mainline: v4.15-rc1
References: bsc#1104967,FATE#325924
MIME-Version: 1.0
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nvm_tgt_types list was protected by wrong lock for NVM_INFO ioctl call
and can race with addition or removal of target types.  Also
unregistering target type was not protected correctly.

Fixes: 5cd907853 ("lightnvm: remove nested lock conflict with mm")
Signed-off-by: Rakesh Pandit <rakesh@tuxera.com>
Reviewed-by: Javier González <javier@cnexlabs.com>
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Hannes Reinecke <hare@suse.com>
---
 drivers/lightnvm/core.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/lightnvm/core.c b/drivers/lightnvm/core.c
index c490711cf0f4..ee2b6d771990 100644
--- a/drivers/lightnvm/core.c
+++ b/drivers/lightnvm/core.c
@@ -589,9 +589,9 @@ void nvm_unregister_tgt_type(struct nvm_tgt_type *tt)
 	if (!tt)
 		return;
 
-	down_write(&nvm_lock);
+	down_write(&nvm_tgtt_lock);
 	list_del(&tt->list);
-	up_write(&nvm_lock);
+	up_write(&nvm_tgtt_lock);
 }
 EXPORT_SYMBOL(nvm_unregister_tgt_type);
 
@@ -1195,7 +1195,7 @@ static long nvm_ioctl_info(struct file *file, void __user *arg)
 	info->version[1] = NVM_VERSION_MINOR;
 	info->version[2] = NVM_VERSION_PATCH;
 
-	down_write(&nvm_lock);
+	down_write(&nvm_tgtt_lock);
 	list_for_each_entry(tt, &nvm_tgt_types, list) {
 		struct nvm_ioctl_info_tgt *tgt = &info->tgts[tgt_iter];
 
@@ -1208,7 +1208,7 @@ static long nvm_ioctl_info(struct file *file, void __user *arg)
 	}
 
 	info->tgtsize = tgt_iter;
-	up_write(&nvm_lock);
+	up_write(&nvm_tgtt_lock);
 
 	if (copy_to_user(arg, info, sizeof(struct nvm_ioctl_info))) {
 		kfree(info);
-- 
2.12.3