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Commit e9ab41b6 authored by Trond Myklebust's avatar Trond Myklebust
Browse files

NFSv4: Clean up the legacy idmapper upcall 



Replace the BUG_ON(idmap->idmap_key_cons != NULL) with a
WARN_ON_ONCE(). Then get rid of the ACCESS_ONCE(idmap->idmap_key_cons).

Then add helper functions for starting, finishing and aborting the
legacy upcall.

Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: Bryan Schumaker <bjschuma@netapp.com>
parent 0e24d849

fs/nfs/idmap.c

+44 −21
Original line number Diff line number Diff line
@@ -330,7 +330,6 @@ static ssize_t nfs_idmap_get_key(const char *name, size_t namelen, 
		ret = nfs_idmap_request_key(&key_type_id_resolver_legacy,

					    name, namelen, type, data,

					    data_size, idmap);

		idmap->idmap_key_cons = NULL;

		mutex_unlock(&idmap->idmap_mutex);

	}

	return ret;
@@ -662,6 +661,34 @@ static int nfs_idmap_prepare_message(char *desc, struct idmap *idmap, 
	return ret;

}



static bool

nfs_idmap_prepare_pipe_upcall(struct idmap *idmap,

		struct key_construction *cons)

{

	if (idmap->idmap_key_cons != NULL) {

		WARN_ON_ONCE(1);

		return false;

	}

	idmap->idmap_key_cons = cons;

	return true;

}



static void

nfs_idmap_complete_pipe_upcall_locked(struct idmap *idmap, int ret)

{

	struct key_construction *cons = idmap->idmap_key_cons;



	idmap->idmap_key_cons = NULL;

	complete_request_key(cons, ret);

}



static void

nfs_idmap_abort_pipe_upcall(struct idmap *idmap, int ret)

{

	if (idmap->idmap_key_cons != NULL)

		nfs_idmap_complete_pipe_upcall_locked(idmap, ret);

}



static int nfs_idmap_legacy_upcall(struct key_construction *cons,

				   const char *op,

				   void *aux)
@@ -686,21 +713,17 @@ static int nfs_idmap_legacy_upcall(struct key_construction *cons, 
	if (ret < 0)

		goto out2;



	if (idmap->idmap_key_cons != NULL) {

		WARN_ON_ONCE(1);

	ret = -EAGAIN;

	if (!nfs_idmap_prepare_pipe_upcall(idmap, cons))

		goto out2;

	}

	idmap->idmap_key_cons = cons;



	ret = rpc_queue_upcall(idmap->idmap_pipe, msg);

	if (ret < 0)

		goto out3;

	if (ret < 0) {

		nfs_idmap_abort_pipe_upcall(idmap, ret);

		kfree(data);

	}



	return ret;



out3:

	idmap->idmap_key_cons = NULL;

out2:

	kfree(data);

out1:
@@ -741,14 +764,15 @@ idmap_pipe_downcall(struct file *filp, const char __user *src, size_t mlen) 
	struct key_construction *cons;

	struct idmap_msg im;

	size_t namelen_in;

	int ret;

	int ret = -ENOKEY;



	/* If instantiation is successful, anyone waiting for key construction

	 * will have been woken up and someone else may now have used

	 * idmap_key_cons - so after this point we may no longer touch it.

	 */

	cons = idmap->idmap_key_cons;

	idmap->idmap_key_cons = NULL;

	if (cons == NULL)

		goto out_noupcall;



	if (mlen != sizeof(im)) {

		ret = -ENOSPC;
@@ -778,7 +802,8 @@ idmap_pipe_downcall(struct file *filp, const char __user *src, size_t mlen) 
	}



out:

	complete_request_key(cons, ret);

	nfs_idmap_complete_pipe_upcall_locked(idmap, ret);

out_noupcall:

	return ret;

}
@@ -789,12 +814,9 @@ idmap_pipe_destroy_msg(struct rpc_pipe_msg *msg) 
			struct idmap_legacy_upcalldata,

			pipe_msg);

	struct idmap *idmap = data->idmap;

	struct key_construction *cons;

	if (msg->errno) {

		cons = idmap->idmap_key_cons;

		idmap->idmap_key_cons = NULL;

		complete_request_key(cons, msg->errno);

	}



	if (msg->errno)

		nfs_idmap_abort_pipe_upcall(idmap, msg->errno);

	/* Free memory allocated in nfs_idmap_legacy_upcall() */

	kfree(data);

}
@@ -804,7 +826,8 @@ idmap_release_pipe(struct inode *inode) 
{

	struct rpc_inode *rpci = RPC_I(inode);

	struct idmap *idmap = (struct idmap *)rpci->private;

	idmap->idmap_key_cons = NULL;



	nfs_idmap_abort_pipe_upcall(idmap, -EPIPE);

}



int nfs_map_name_to_uid(const struct nfs_server *server, const char *name, size_t namelen, __u32 *uid)