This is a note to let you know that I've just added the patch titled

nfsd: fix panic in posix_unblock_lock called from nfs4_laundromat

to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: nfsd-fix-panic-in-posix_unblock_lock-called-from-nfs4_laundromat.patch and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From 64ebe12494fd5d193f014ce38e1fd83cc57883c8 Mon Sep 17 00:00:00 2001

From: Naofumi Honda honda@math.sci.hokudai.ac.jp Date: Thu, 9 Nov 2017 10:57:16 -0500 Subject: nfsd: fix panic in posix_unblock_lock called from nfs4_laundromat

From: Naofumi Honda honda@math.sci.hokudai.ac.jp

commit 64ebe12494fd5d193f014ce38e1fd83cc57883c8 upstream.

From kernel 4.9, my two nfsv4 servers sometimes suffer from

"panic: unable to handle kernel page request" in posix_unblock_lock() called from nfs4_laundromat().

These panics diseappear if we revert the commit "nfsd: add a LRU list for blocked locks".

The cause appears to be a typo in nfs4_laundromat(), which is also present in nfs4_state_shutdown_net().

Fixes: 7919d0a27f1e "nfsd: add a LRU list for blocked locks" Cc: jlayton@redhat.com Reveiwed-by: Jeff Layton jlayton@redhat.com Signed-off-by: J. Bruce Fields bfields@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- fs/nfsd/nfs4state.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -4732,7 +4732,7 @@ nfs4_laundromat(struct nfsd_net *nn) spin_unlock(&nn->blocked_locks_lock);

while (!list_empty(&reaplist)) { - nbl = list_first_entry(&nn->blocked_locks_lru, + nbl = list_first_entry(&reaplist, struct nfsd4_blocked_lock, nbl_lru); list_del_init(&nbl->nbl_lru); posix_unblock_lock(&nbl->nbl_lock); @@ -7143,7 +7143,7 @@ nfs4_state_shutdown_net(struct net *net) spin_unlock(&nn->blocked_locks_lock);

while (!list_empty(&reaplist)) { - nbl = list_first_entry(&nn->blocked_locks_lru, + nbl = list_first_entry(&reaplist, struct nfsd4_blocked_lock, nbl_lru); list_del_init(&nbl->nbl_lru); posix_unblock_lock(&nbl->nbl_lock);

Patches currently in stable-queue which might be from honda@math.sci.hokudai.ac.jp are

queue-4.9/nfsd-fix-panic-in-posix_unblock_lock-called-from-nfs4_laundromat.patch