[PATCH] quota: add missing lock into __dquot_transfer()

[Konstantin Khlebnikov]

Lock dq_dqb_lock around dquot_decr_inodes()

Signed-off-by: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxxxxxx>
Fixes: 7b9ca4c61bc2 ("quota: Reduce contention on dq_data_lock")
---
 fs/quota/dquot.c |    2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index 8381db9db6d9..50b0556a124f 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -1980,7 +1980,9 @@ int __dquot_transfer(struct inode *inode, struct dquot **transfer_to)
 		ret = dquot_add_space(transfer_to[cnt], cur_space, rsv_space, 0,
 				      &warn_to[cnt]);
 		if (ret) {
+			spin_lock(&transfer_to[cnt]->dq_dqb_lock);
 			dquot_decr_inodes(transfer_to[cnt], inode_usage);
+			spin_unlock(&transfer_to[cnt]->dq_dqb_lock);
 			goto over_quota;
 		}
 	}