From 9ae075fdd1901b60d87a0404f9c110753e16969a Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Sun, 2 Sep 2018 19:15:15 -0400 Subject: NFSv4: Convert open state lookup to use RCU Further reduce contention on the inode->i_lock. Signed-off-by: Trond Myklebust --- fs/nfs/nfs4_fs.h | 1 + fs/nfs/nfs4state.c | 12 ++++++------ 2 files changed, 7 insertions(+), 6 deletions(-) diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h index 3a6904173214..1b4737f4cac4 100644 --- a/fs/nfs/nfs4_fs.h +++ b/fs/nfs/nfs4_fs.h @@ -191,6 +191,7 @@ struct nfs4_state { atomic_t count; wait_queue_head_t waitq; + struct rcu_head rcu_head; }; diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c index be92ce4259e9..7feac365038c 100644 --- a/fs/nfs/nfs4state.c +++ b/fs/nfs/nfs4state.c @@ -684,7 +684,7 @@ __nfs4_find_state_byowner(struct inode *inode, struct nfs4_state_owner *owner) struct nfs_inode *nfsi = NFS_I(inode); struct nfs4_state *state; - list_for_each_entry(state, &nfsi->open_states, inode_states) { + list_for_each_entry_rcu(state, &nfsi->open_states, inode_states) { if (state->owner != owner) continue; if (!nfs4_valid_open_stateid(state)) @@ -698,7 +698,7 @@ __nfs4_find_state_byowner(struct inode *inode, struct nfs4_state_owner *owner) static void nfs4_free_open_state(struct nfs4_state *state) { - kfree(state); + kfree_rcu(state, rcu_head); } struct nfs4_state * @@ -707,9 +707,9 @@ nfs4_get_open_state(struct inode *inode, struct nfs4_state_owner *owner) struct nfs4_state *state, *new; struct nfs_inode *nfsi = NFS_I(inode); - spin_lock(&inode->i_lock); + rcu_read_lock(); state = __nfs4_find_state_byowner(inode, owner); - spin_unlock(&inode->i_lock); + rcu_read_unlock(); if (state) goto out; new = nfs4_alloc_open_state(); @@ -720,7 +720,7 @@ nfs4_get_open_state(struct inode *inode, struct nfs4_state_owner *owner) state = new; state->owner = owner; atomic_inc(&owner->so_count); - list_add(&state->inode_states, &nfsi->open_states); + list_add_rcu(&state->inode_states, &nfsi->open_states); ihold(inode); state->inode = inode; spin_unlock(&inode->i_lock); @@ -746,7 +746,7 @@ void nfs4_put_open_state(struct nfs4_state *state) if (!atomic_dec_and_lock(&state->count, &owner->so_lock)) return; spin_lock(&inode->i_lock); - list_del(&state->inode_states); + list_del_rcu(&state->inode_states); list_del(&state->open_states); spin_unlock(&inode->i_lock); spin_unlock(&owner->so_lock); -- cgit v1.2.3