NFSv4: Convert LOCK rpc call into an asynchronous RPC call

 In order to allow users to interrupt/cancel it.

 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

2 files changed, 175 insertions, 75 deletions

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 857125705b6f..718fcc722556 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -3100,11 +3100,30 @@ static const struct rpc_call_ops nfs4_locku_ops = {
         .rpc_release = nfs4_locku_release_calldata,
 };
 
+static struct rpc_task *nfs4_do_unlck(struct file_lock *fl,
+                struct nfs_open_context *ctx,
+                struct nfs4_lock_state *lsp,
+                struct nfs_seqid *seqid)
+{
+        struct nfs4_unlockdata *data;
+        struct rpc_task *task;
+
+        data = nfs4_alloc_unlockdata(fl, ctx, lsp, seqid);
+        if (data == NULL) {
+                nfs_free_seqid(seqid);
+                return ERR_PTR(-ENOMEM);
+        }
+
+        /* Unlock _before_ we do the RPC call */
+        do_vfs_lock(fl->fl_file, fl);
+        task = rpc_run_task(NFS_CLIENT(lsp->ls_state->inode), RPC_TASK_ASYNC, &nfs4_locku_ops, data);
+        if (IS_ERR(task))
+                nfs4_locku_release_calldata(data);
+        return task;
+}
+
 static int nfs4_proc_unlck(struct nfs4_state *state, int cmd, struct file_lock *request)
 {
-        struct nfs4_unlockdata *calldata;
-        struct inode *inode = state->inode;
-        struct nfs_server *server = NFS_SERVER(inode);
         struct nfs_seqid *seqid;
         struct nfs4_lock_state *lsp;
         struct rpc_task *task;
@@ -3125,86 +3144,173 @@ static int nfs4_proc_unlck(struct nfs4_state *state, int cmd, struct file_lock *
         seqid = nfs_alloc_seqid(&lsp->ls_seqid);
         if (seqid == NULL)
                 goto out_unlock;
-        calldata = nfs4_alloc_unlockdata(request, request->fl_file->private_data,
-                        lsp, seqid);
-        if (calldata == NULL)
-                goto out_free_seqid;
-        /* Unlock _before_ we do the RPC call */
-        do_vfs_lock(request->fl_file, request);
-        task = rpc_run_task(server->client, RPC_TASK_ASYNC, &nfs4_locku_ops, calldata);
-        if (!IS_ERR(task)) {
-                status = nfs4_wait_for_completion_rpc_task(task);
-                rpc_release_task(task);
-        } else {
-                status = PTR_ERR(task);
-                nfs4_locku_release_calldata(calldata);
-        }
+        task = nfs4_do_unlck(request, request->fl_file->private_data, lsp, seqid);
+        status = PTR_ERR(task);
+        if (IS_ERR(task))
+                goto out_unlock;
+        status = nfs4_wait_for_completion_rpc_task(task);
+        rpc_release_task(task);
         return status;
-out_free_seqid:
-        nfs_free_seqid(seqid);
 out_unlock:
         do_vfs_lock(request->fl_file, request);
         return status;
 }
 
-static int _nfs4_do_setlk(struct nfs4_state *state, int cmd, struct file_lock *request, int reclaim)
+struct nfs4_lockdata {
+        struct nfs_lock_args arg;
+        struct nfs_lock_res res;
+        struct nfs4_lock_state *lsp;
+        struct nfs_open_context *ctx;
+        struct file_lock fl;
+        int rpc_status;
+        int cancelled;
+};
+
+static struct nfs4_lockdata *nfs4_alloc_lockdata(struct file_lock *fl,
+                struct nfs_open_context *ctx, struct nfs4_lock_state *lsp)
 {
-        struct inode *inode = state->inode;
+        struct nfs4_lockdata *p;
+        struct inode *inode = lsp->ls_state->inode;
         struct nfs_server *server = NFS_SERVER(inode);
-        struct nfs4_lock_state *lsp = request->fl_u.nfs4_fl.owner;
-        struct nfs_lock_args arg = {
-                .fh = NFS_FH(inode),
-                .fl = request,
-                .lock_stateid = &lsp->ls_stateid,
-                .open_stateid = &state->stateid,
-                .lock_owner = {
-                        .clientid = server->nfs4_state->cl_clientid,
-                        .id = lsp->ls_id,
-                },
-                .block = (IS_SETLKW(cmd)) ? 1 : 0,
-                .reclaim = reclaim,
-        };
-        struct nfs_lock_res res;
+
+        p = kzalloc(sizeof(*p), GFP_KERNEL);
+        if (p == NULL)
+                return NULL;
+
+        p->arg.fh = NFS_FH(inode);
+        p->arg.fl = &p->fl;
+        p->arg.lock_seqid = nfs_alloc_seqid(&lsp->ls_seqid);
+        if (p->arg.lock_seqid == NULL)
+                goto out_free;
+        p->arg.lock_stateid = &lsp->ls_stateid;
+        p->arg.lock_owner.clientid = server->nfs4_state->cl_clientid;
+        p->arg.lock_owner.id = lsp->ls_id;
+        p->lsp = lsp;
+        atomic_inc(&lsp->ls_count);
+        p->ctx = get_nfs_open_context(ctx);
+        memcpy(&p->fl, fl, sizeof(p->fl));
+        return p;
+out_free:
+        kfree(p);
+        return NULL;
+}
+
+static void nfs4_lock_prepare(struct rpc_task *task, void *calldata)
+{
+        struct nfs4_lockdata *data = calldata;
+        struct nfs4_state *state = data->lsp->ls_state;
+        struct nfs4_state_owner *sp = state->owner;
         struct rpc_message msg = {
-                .rpc_proc       = &nfs4_procedures[NFSPROC4_CLNT_LOCK],
-                .rpc_argp       = &arg,
-                .rpc_resp       = &res,
-                .rpc_cred       = state->owner->so_cred,
+                .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_LOCK],
+                .rpc_argp = &data->arg,
+                .rpc_resp = &data->res,
+                .rpc_cred = sp->so_cred,
         };
-        int status = -ENOMEM;
-
-        arg.lock_seqid = nfs_alloc_seqid(&lsp->ls_seqid);
-        if (arg.lock_seqid == NULL)
-                return -ENOMEM;
-        if (!(lsp->ls_seqid.flags & NFS_SEQID_CONFIRMED)) {
-                struct nfs4_state_owner *owner = state->owner;
 
-                arg.open_seqid = nfs_alloc_seqid(&owner->so_seqid);
-                if (arg.open_seqid == NULL)
+        if (nfs_wait_on_sequence(data->arg.lock_seqid, task) != 0)
+                return;
+        dprintk("%s: begin!\n", __FUNCTION__);
+        /* Do we need to do an open_to_lock_owner? */
+        if (!(data->arg.lock_seqid->sequence->flags & NFS_SEQID_CONFIRMED)) {
+                data->arg.open_seqid = nfs_alloc_seqid(&sp->so_seqid);
+                if (data->arg.open_seqid == NULL) {
+                        data->rpc_status = -ENOMEM;
+                        task->tk_action = NULL;
                         goto out;
-                arg.new_lock_owner = 1;
-                status = rpc_call_sync(server->client, &msg, RPC_TASK_NOINTR);
-                /* increment open seqid on success, and seqid mutating errors */
-                if (arg.new_lock_owner != 0) {
-                        nfs_increment_open_seqid(status, arg.open_seqid);
-                        if (status == 0)
-                                nfs_confirm_seqid(&lsp->ls_seqid, 0);
                 }
-                nfs_free_seqid(arg.open_seqid);
-        } else
-                status = rpc_call_sync(server->client, &msg, RPC_TASK_NOINTR);
-        /* increment lock seqid on success, and seqid mutating errors*/
-        nfs_increment_lock_seqid(status, arg.lock_seqid);
-        /* save the returned stateid. */
-        if (status == 0) {
-                memcpy(lsp->ls_stateid.data, res.stateid.data,
-                                sizeof(lsp->ls_stateid.data));
-                lsp->ls_flags |= NFS_LOCK_INITIALIZED;
-        } else if (status == -NFS4ERR_DENIED)
-                status = -EAGAIN;
+                data->arg.open_stateid = &state->stateid;
+                data->arg.new_lock_owner = 1;
+        }
+        rpc_call_setup(task, &msg, 0);
 out:
-        nfs_free_seqid(arg.lock_seqid);
-        return status;
+        dprintk("%s: done!, ret = %d\n", __FUNCTION__, data->rpc_status);
+}
+
+static void nfs4_lock_done(struct rpc_task *task, void *calldata)
+{
+        struct nfs4_lockdata *data = calldata;
+
+        dprintk("%s: begin!\n", __FUNCTION__);
+
+        data->rpc_status = task->tk_status;
+        if (RPC_ASSASSINATED(task))
+                goto out;
+        if (data->arg.new_lock_owner != 0) {
+                nfs_increment_open_seqid(data->rpc_status, data->arg.open_seqid);
+                if (data->rpc_status == 0)
+                        nfs_confirm_seqid(&data->lsp->ls_seqid, 0);
+                else
+                        goto out;
+        }
+        if (data->rpc_status == 0) {
+                memcpy(data->lsp->ls_stateid.data, data->res.stateid.data,
+                                        sizeof(data->lsp->ls_stateid.data));
+                data->lsp->ls_flags |= NFS_LOCK_INITIALIZED;
+        }
+        nfs_increment_lock_seqid(data->rpc_status, data->arg.lock_seqid);
+out:
+        dprintk("%s: done, ret = %d!\n", __FUNCTION__, data->rpc_status);
+}
+
+static void nfs4_lock_release(void *calldata)
+{
+        struct nfs4_lockdata *data = calldata;
+
+        dprintk("%s: begin!\n", __FUNCTION__);
+        if (data->arg.open_seqid != NULL)
+                nfs_free_seqid(data->arg.open_seqid);
+        if (data->cancelled != 0) {
+                struct rpc_task *task;
+                task = nfs4_do_unlck(&data->fl, data->ctx, data->lsp,
+                                data->arg.lock_seqid);
+                if (!IS_ERR(task))
+                        rpc_release_task(task);
+                dprintk("%s: cancelling lock!\n", __FUNCTION__);
+        } else
+                nfs_free_seqid(data->arg.lock_seqid);
+        nfs4_put_lock_state(data->lsp);
+        put_nfs_open_context(data->ctx);
+        kfree(data);
+        dprintk("%s: done!\n", __FUNCTION__);
+}
+
+static const struct rpc_call_ops nfs4_lock_ops = {
+        .rpc_call_prepare = nfs4_lock_prepare,
+        .rpc_call_done = nfs4_lock_done,
+        .rpc_release = nfs4_lock_release,
+};
+
+static int _nfs4_do_setlk(struct nfs4_state *state, int cmd, struct file_lock *fl, int reclaim)
+{
+        struct nfs4_lockdata *data;
+        struct rpc_task *task;
+        int ret;
+
+        dprintk("%s: begin!\n", __FUNCTION__);
+        data = nfs4_alloc_lockdata(fl, fl->fl_file->private_data,
+                        fl->fl_u.nfs4_fl.owner);
+        if (data == NULL)
+                return -ENOMEM;
+        if (IS_SETLKW(cmd))
+                data->arg.block = 1;
+        if (reclaim != 0)
+                data->arg.reclaim = 1;
+        task = rpc_run_task(NFS_CLIENT(state->inode), RPC_TASK_ASYNC,
+                        &nfs4_lock_ops, data);
+        if (IS_ERR(task)) {
+                nfs4_lock_release(data);
+                return PTR_ERR(task);
+        }
+        ret = nfs4_wait_for_completion_rpc_task(task);
+        if (ret == 0) {
+                ret = data->rpc_status;
+                if (ret == -NFS4ERR_DENIED)
+                        ret = -EAGAIN;
+        } else
+                data->cancelled = 1;
+        rpc_release_task(task);
+        dprintk("%s: done, ret = %d!\n", __FUNCTION__, ret);
+        return ret;
 }
 
 static int nfs4_lock_reclaim(struct nfs4_state *state, struct file_lock *request)
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index a7b5de899c6d..5d6bda43dfaa 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -1615,12 +1615,6 @@ static int nfs4_xdr_enc_lock(struct rpc_rqst *req, uint32_t *p, struct nfs_lock_
         };
         int status;
 
-        status = nfs_wait_on_sequence(args->lock_seqid, req->rq_task);
-        if (status != 0)
-                goto out;
-        /* Do we need to do an open_to_lock_owner? */
-        if (args->lock_seqid->sequence->flags & NFS_SEQID_CONFIRMED)
-                args->new_lock_owner = 0;
         xdr_init_encode(&xdr, &req->rq_snd_buf, p);
         encode_compound_hdr(&xdr, &hdr);
         status = encode_putfh(&xdr, args->fh);