NFSv4: Fix atomicity problems with lock stateid updates
When we update the lock stateid, we really do need to ensure that this is
done under the state->state_lock, and that we are indeed only updating
confirmed locks with a newer version of the same stateid.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 0a279ad..db9d98e 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -1297,6 +1297,23 @@
return ret;
}
+static bool nfs4_update_lock_stateid(struct nfs4_lock_state *lsp,
+ const nfs4_stateid *stateid)
+{
+ struct nfs4_state *state = lsp->ls_state;
+ bool ret = false;
+
+ spin_lock(&state->state_lock);
+ if (!nfs4_stateid_match_other(stateid, &lsp->ls_stateid))
+ goto out_noupdate;
+ if (!nfs4_stateid_is_newer(stateid, &lsp->ls_stateid))
+ goto out_noupdate;
+ nfs4_stateid_copy(&lsp->ls_stateid, stateid);
+ ret = true;
+out_noupdate:
+ spin_unlock(&state->state_lock);
+ return ret;
+}
static void nfs4_return_incompatible_delegation(struct inode *inode, fmode_t fmode)
{
@@ -5403,9 +5420,9 @@
return;
switch (task->tk_status) {
case 0:
- nfs4_stateid_copy(&calldata->lsp->ls_stateid,
- &calldata->res.stateid);
renew_lease(calldata->server, calldata->timestamp);
+ nfs4_update_lock_stateid(calldata->lsp,
+ &calldata->res.stateid);
break;
case -NFS4ERR_BAD_STATEID:
case -NFS4ERR_OLD_STATEID:
@@ -5626,6 +5643,7 @@
static void nfs4_lock_done(struct rpc_task *task, void *calldata)
{
struct nfs4_lockdata *data = calldata;
+ struct nfs4_lock_state *lsp = data->lsp;
dprintk("%s: begin!\n", __func__);
@@ -5633,18 +5651,16 @@
return;
data->rpc_status = task->tk_status;
- if (data->arg.new_lock_owner != 0) {
- if (data->rpc_status == 0)
- nfs_confirm_seqid(&data->lsp->ls_seqid, 0);
- else
- goto out;
+ if (task->tk_status == 0) {
+ renew_lease(NFS_SERVER(data->ctx->dentry->d_inode),
+ data->timestamp);
+ if (data->arg.new_lock_owner != 0) {
+ nfs_confirm_seqid(&lsp->ls_seqid, 0);
+ nfs4_stateid_copy(&lsp->ls_stateid, &data->res.stateid);
+ set_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags);
+ } else if (!nfs4_update_lock_stateid(lsp, &data->res.stateid))
+ rpc_restart_call_prepare(task);
}
- if (data->rpc_status == 0) {
- nfs4_stateid_copy(&data->lsp->ls_stateid, &data->res.stateid);
- set_bit(NFS_LOCK_INITIALIZED, &data->lsp->ls_flags);
- renew_lease(NFS_SERVER(data->ctx->dentry->d_inode), data->timestamp);
- }
-out:
dprintk("%s: done, ret = %d!\n", __func__, data->rpc_status);
}