From bc2940869508b7b956a757a26d3b1ebf9546790e Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Wed, 23 Oct 2024 16:34:42 -0400 Subject: nfs_common: fix localio to cope with racing nfs_local_probe() Fix the possibility of racing nfs_local_probe() resulting in: list_add double add: new=ffff8b99707f9f58, prev=ffff8b99707f9f58, next=ffffffffc0f30000. ------------[ cut here ]------------ kernel BUG at lib/list_debug.c:35! Add nfs_uuid_init() to properly initialize all nfs_uuid_t members (particularly its list_head). Switch to returning bool from nfs_uuid_begin(), returns false if nfs_uuid_t is already in-use (its list_head is on a list). Update nfs_local_probe() to return early if the nfs_client's cl_uuid (nfs_uuid_t) is in-use. Also, switch nfs_uuid_begin() from using list_add_tail_rcu() to list_add_tail() -- rculist was used in an earlier version of the localio code that had a lockless nfs_uuid_lookup interface. Signed-off-by: Mike Snitzer Signed-off-by: Anna Schumaker --- include/linux/nfslocalio.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/nfslocalio.h b/include/linux/nfslocalio.h index b0dd9b1eef4f..3982fea79919 100644 --- a/include/linux/nfslocalio.h +++ b/include/linux/nfslocalio.h @@ -32,7 +32,8 @@ typedef struct { struct auth_domain *dom; /* auth_domain for localio */ } nfs_uuid_t; -void nfs_uuid_begin(nfs_uuid_t *); +void nfs_uuid_init(nfs_uuid_t *); +bool nfs_uuid_begin(nfs_uuid_t *); void nfs_uuid_end(nfs_uuid_t *); void nfs_uuid_is_local(const uuid_t *, struct list_head *, struct net *, struct auth_domain *, struct module *); -- cgit v1.2.3