mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-11-20 16:46:23 +08:00
NFSv4: Check for the existence of a delegation in nfs4_open_prepare()
We should not be calling open() on an inode that has a delegation unless we're doing a reclaim. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Trond Myklebust
parent
3e309914a1
commit
aac00a8d0a
@ -65,6 +65,7 @@ static int nfs4_async_handle_error(struct rpc_task *, const struct nfs_server *)
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static int _nfs4_proc_access(struct inode *inode, struct nfs_access_entry *entry);
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static int nfs4_handle_exception(const struct nfs_server *server, int errorcode, struct nfs4_exception *exception);
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static int nfs4_wait_clnt_recover(struct rpc_clnt *clnt, struct nfs_client *clp);
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static int _nfs4_do_access(struct inode *inode, struct rpc_cred *cred, int openflags);
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/* Prevent leaks of NFSv4 errors into userland */
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int nfs4_map_errors(int err)
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@ -224,6 +225,7 @@ struct nfs4_opendata {
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struct path path;
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struct dentry *dir;
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struct nfs4_state_owner *owner;
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struct nfs4_state *state;
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struct iattr attrs;
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unsigned long timestamp;
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unsigned int rpc_done : 1;
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@ -296,6 +298,8 @@ static void nfs4_opendata_free(struct kref *kref)
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struct nfs4_opendata, kref);
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nfs_free_seqid(p->o_arg.seqid);
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if (p->state != NULL)
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nfs4_put_open_state(p->state);
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nfs4_put_state_owner(p->owner);
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dput(p->dir);
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dput(p->path.dentry);
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@ -320,6 +324,15 @@ static int nfs4_wait_for_completion_rpc_task(struct rpc_task *task)
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return ret;
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}
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static int can_open_delegated(struct nfs_delegation *delegation, mode_t open_flags)
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{
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if ((delegation->type & open_flags) != open_flags)
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return 0;
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if (delegation->flags & NFS_DELEGATION_NEED_RECLAIM)
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return 0;
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return 1;
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}
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static void update_open_stateflags(struct nfs4_state *state, mode_t open_flags)
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{
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switch (open_flags) {
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@ -380,6 +393,65 @@ static void update_open_stateid(struct nfs4_state *state, nfs4_stateid *open_sta
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spin_unlock(&state->owner->so_lock);
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}
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static void nfs4_return_incompatible_delegation(struct inode *inode, mode_t open_flags)
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{
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struct nfs_delegation *delegation;
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rcu_read_lock();
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delegation = rcu_dereference(NFS_I(inode)->delegation);
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if (delegation == NULL || (delegation->type & open_flags) == open_flags) {
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rcu_read_unlock();
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return;
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}
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rcu_read_unlock();
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nfs_inode_return_delegation(inode);
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}
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static struct nfs4_state *nfs4_try_open_delegated(struct nfs4_opendata *opendata)
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{
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struct nfs4_state *state = opendata->state;
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struct nfs_inode *nfsi = NFS_I(state->inode);
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struct nfs_delegation *delegation;
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int open_mode = opendata->o_arg.open_flags & (FMODE_READ|FMODE_WRITE|O_EXCL);
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nfs4_stateid stateid;
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int ret = -EAGAIN;
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rcu_read_lock();
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delegation = rcu_dereference(nfsi->delegation);
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if (delegation == NULL)
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goto out_unlock;
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for (;;) {
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if (!can_open_delegated(delegation, open_mode))
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break;
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/* Save the delegation */
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memcpy(stateid.data, delegation->stateid.data, sizeof(stateid.data));
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rcu_read_unlock();
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lock_kernel();
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ret = _nfs4_do_access(state->inode, state->owner->so_cred, open_mode);
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unlock_kernel();
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if (ret != 0)
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goto out;
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ret = -EAGAIN;
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rcu_read_lock();
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delegation = rcu_dereference(nfsi->delegation);
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if (delegation == NULL)
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break;
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/* Is the delegation still valid? */
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if (memcmp(stateid.data, delegation->stateid.data, sizeof(stateid.data)) != 0)
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continue;
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rcu_read_unlock();
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update_open_stateid(state, NULL, &stateid, open_mode);
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goto out_return_state;
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}
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out_unlock:
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rcu_read_unlock();
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out:
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return ERR_PTR(ret);
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out_return_state:
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atomic_inc(&state->count);
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return state;
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}
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static struct nfs4_state *nfs4_opendata_to_nfs4_state(struct nfs4_opendata *data)
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{
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struct inode *inode;
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@ -388,6 +460,11 @@ static struct nfs4_state *nfs4_opendata_to_nfs4_state(struct nfs4_opendata *data
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nfs4_stateid *deleg_stateid = NULL;
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int ret;
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if (!data->rpc_done) {
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state = nfs4_try_open_delegated(data);
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goto out;
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}
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ret = -EAGAIN;
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if (!(data->f_attr.valid & NFS_ATTR_FATTR))
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goto err;
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@ -423,6 +500,7 @@ static struct nfs4_state *nfs4_opendata_to_nfs4_state(struct nfs4_opendata *data
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update_open_stateid(state, &data->o_res.stateid, deleg_stateid, data->o_arg.open_flags);
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rcu_read_unlock();
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iput(inode);
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out:
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return state;
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err_put_inode:
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iput(inode);
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@ -690,6 +768,23 @@ static void nfs4_open_prepare(struct rpc_task *task, void *calldata)
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if (nfs_wait_on_sequence(data->o_arg.seqid, task) != 0)
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return;
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/*
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* Check if we still need to send an OPEN call, or if we can use
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* a delegation instead.
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*/
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if (data->state != NULL) {
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struct nfs_delegation *delegation;
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rcu_read_lock();
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delegation = rcu_dereference(NFS_I(data->state->inode)->delegation);
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if (delegation != NULL &&
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(delegation->flags & NFS_DELEGATION_NEED_RECLAIM) == 0) {
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rcu_read_unlock();
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task->tk_action = NULL;
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return;
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}
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rcu_read_unlock();
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}
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/* Update sequence id. */
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data->o_arg.id = sp->so_owner_id.id;
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data->o_arg.clientid = sp->so_client->cl_clientid;
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@ -906,90 +1001,6 @@ static int nfs4_open_expired(struct nfs4_state_owner *sp, struct nfs4_state *sta
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return ret;
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}
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/*
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* Returns a referenced nfs4_state if there is an open delegation on the file
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*/
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static int _nfs4_open_delegated(struct inode *inode, int flags, struct rpc_cred *cred, struct nfs4_state **res)
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{
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struct nfs_delegation *delegation;
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struct nfs_server *server = NFS_SERVER(inode);
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struct nfs_client *clp = server->nfs_client;
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struct nfs_inode *nfsi = NFS_I(inode);
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struct nfs4_state_owner *sp = NULL;
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struct nfs4_state *state = NULL;
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int open_flags = flags & (FMODE_READ|FMODE_WRITE);
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int err;
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err = -ENOMEM;
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if (!(sp = nfs4_get_state_owner(server, cred))) {
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dprintk("%s: nfs4_get_state_owner failed!\n", __FUNCTION__);
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return err;
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}
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err = nfs4_recover_expired_lease(server);
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if (err != 0)
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goto out_put_state_owner;
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/* Protect against reboot recovery - NOTE ORDER! */
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down_read(&clp->cl_sem);
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/* Protect against delegation recall */
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down_read(&nfsi->rwsem);
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delegation = NFS_I(inode)->delegation;
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err = -ENOENT;
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if (delegation == NULL || (delegation->type & open_flags) != open_flags)
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goto out_err;
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err = -ENOMEM;
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state = nfs4_get_open_state(inode, sp);
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if (state == NULL)
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goto out_err;
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err = -ENOENT;
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if ((state->state & open_flags) == open_flags) {
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spin_lock(&inode->i_lock);
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update_open_stateflags(state, open_flags);
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spin_unlock(&inode->i_lock);
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goto out_ok;
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} else if (state->state != 0)
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goto out_put_open_state;
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lock_kernel();
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err = _nfs4_do_access(inode, cred, open_flags);
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unlock_kernel();
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if (err != 0)
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goto out_put_open_state;
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update_open_stateid(state, NULL, &delegation->stateid, open_flags);
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out_ok:
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nfs4_put_state_owner(sp);
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up_read(&nfsi->rwsem);
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up_read(&clp->cl_sem);
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*res = state;
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return 0;
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out_put_open_state:
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nfs4_put_open_state(state);
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out_err:
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up_read(&nfsi->rwsem);
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up_read(&clp->cl_sem);
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if (err != -EACCES)
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nfs_inode_return_delegation(inode);
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out_put_state_owner:
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nfs4_put_state_owner(sp);
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return err;
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}
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static struct nfs4_state *nfs4_open_delegated(struct inode *inode, int flags, struct rpc_cred *cred)
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{
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struct nfs4_exception exception = { };
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struct nfs4_state *res = ERR_PTR(-EIO);
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int err;
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do {
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err = _nfs4_open_delegated(inode, flags, cred, &res);
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if (err == 0)
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break;
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res = ERR_PTR(nfs4_handle_exception(NFS_SERVER(inode),
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err, &exception));
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} while (exception.retry);
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return res;
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}
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/*
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* on an EXCLUSIVE create, the server should send back a bitmask with FATTR4-*
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* fields corresponding to attributes that were used to store the verifier.
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@ -1027,12 +1038,17 @@ static int _nfs4_do_open(struct inode *dir, struct path *path, int flags, struct
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status = nfs4_recover_expired_lease(server);
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if (status != 0)
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goto err_put_state_owner;
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if (path->dentry->d_inode != NULL)
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nfs4_return_incompatible_delegation(path->dentry->d_inode, flags & (FMODE_READ|FMODE_WRITE));
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down_read(&clp->cl_sem);
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status = -ENOMEM;
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opendata = nfs4_opendata_alloc(path, sp, flags, sattr);
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if (opendata == NULL)
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goto err_release_rwsem;
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if (path->dentry->d_inode != NULL)
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opendata->state = nfs4_get_open_state(path->dentry->d_inode, sp);
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status = _nfs4_proc_open(opendata);
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if (status != 0)
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goto err_opendata_put;
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@ -1099,6 +1115,11 @@ static struct nfs4_state *nfs4_do_open(struct inode *dir, struct path *path, int
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exception.retry = 1;
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continue;
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}
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if (status == -EAGAIN) {
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/* We must have found a delegation */
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exception.retry = 1;
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continue;
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}
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res = ERR_PTR(nfs4_handle_exception(NFS_SERVER(dir),
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status, &exception));
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} while (exception.retry);
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@ -1390,8 +1411,6 @@ nfs4_open_revalidate(struct inode *dir, struct dentry *dentry, int openflags, st
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cred = rpcauth_lookupcred(NFS_CLIENT(dir)->cl_auth, 0);
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if (IS_ERR(cred))
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return PTR_ERR(cred);
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state = nfs4_open_delegated(dentry->d_inode, openflags, cred);
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if (IS_ERR(state))
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state = nfs4_do_open(dir, &path, openflags, NULL, cred);
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put_rpccred(cred);
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if (IS_ERR(state)) {
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