NFSv4: Give the lock stateid its own sequence queue

Sharing the open sequence queue causes a deadlock when we try to take
both a lock sequence id and and open sequence id.

This fixes the regression reported by Dimitri Puzin and Jeff Garzik: See

	http://bugzilla.kernel.org/show_bug.cgi?id=9712

for details.

Reported-and-tested-by: Dimitri Puzin <bugs@psycast.de>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Tested-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 5 insertions, 1 deletions

diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
index b35069a2aa9e..bd1b9d663fb9 100644
--- a/fs/nfs/nfs4_fs.h
+++ b/fs/nfs/nfs4_fs.h
@@ -115,6 +115,7 @@ struct nfs4_lock_state {
 #define NFS_LOCK_INITIALIZED 1
         int                     ls_flags;
         struct nfs_seqid_counter        ls_seqid;
+        struct rpc_sequence     ls_sequence;
         struct nfs_unique_id    ls_id;
         nfs4_stateid            ls_stateid;
         atomic_t                ls_count;
diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index 23a9a36556bf..5a39c6f78acf 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -509,7 +509,10 @@ static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, f
         lsp = kzalloc(sizeof(*lsp), GFP_KERNEL);
         if (lsp == NULL)
                 return NULL;
-        lsp->ls_seqid.sequence = &state->owner->so_sequence;
+        rpc_init_wait_queue(&lsp->ls_sequence.wait, "lock_seqid_waitqueue");
+        spin_lock_init(&lsp->ls_sequence.lock);
+        INIT_LIST_HEAD(&lsp->ls_sequence.list);
+        lsp->ls_seqid.sequence = &lsp->ls_sequence;
         atomic_set(&lsp->ls_count, 1);
         lsp->ls_owner = fl_owner;
         spin_lock(&clp->cl_lock);