Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 07d1f802 authored by J. Bruce Fields's avatar J. Bruce Fields
Browse files

nfsd4: fix encoding of out-of-space replies 



If nfsd4_check_resp_size() returns an error then we should really be
truncating the reply here, otherwise we may leave extra garbage at the
end of the rpc reply.

Also add a warning to catch any cases where our reply-size estimates may
be wrong in the case of a non-idempotent operation.

Signed-off-by: default avatarJ. Bruce Fields <bfields@redhat.com>
parent 1802a678

fs/nfsd/nfs4proc.c

+9 −4
Original line number Diff line number Diff line
@@ -1171,9 +1171,7 @@ struct nfsd4_operation { 


static struct nfsd4_operation nfsd4_ops[];



#ifdef NFSD_DEBUG

static const char *nfsd4_op_name(unsigned opnum);

#endif



/*

 * Enforce NFSv4.1 COMPOUND ordering rules:
@@ -1859,14 +1857,21 @@ static struct nfsd4_operation nfsd4_ops[] = { 
	},

};



#ifdef NFSD_DEBUG

void warn_on_nonidempotent_op(struct nfsd4_op *op)

{

	if (OPDESC(op)->op_flags & OP_MODIFIES_SOMETHING) {

		pr_err("unable to encode reply to nonidempotent op %d (%s)\n",

			op->opnum, nfsd4_op_name(op->opnum));

		WARN_ON_ONCE(1);

	}

}



static const char *nfsd4_op_name(unsigned opnum)

{

	if (opnum < ARRAY_SIZE(nfsd4_ops))

		return nfsd4_ops[opnum].op_name;

	return "unknown_operation";

}

#endif



#define nfsd4_voidres			nfsd4_voidargs

struct nfsd4_voidargs { int dummy; };

fs/nfsd/nfs4xdr.c

+16 −1
Original line number Diff line number Diff line
@@ -3637,6 +3637,7 @@ nfsd4_encode_operation(struct nfsd4_compoundres *resp, struct nfsd4_op *op) 
{

	struct nfs4_stateowner *so = resp->cstate.replay_owner;

	__be32 *statp;

	nfsd4_enc encoder;

	__be32 *p;



	RESERVE_SPACE(8);
@@ -3648,10 +3649,24 @@ nfsd4_encode_operation(struct nfsd4_compoundres *resp, struct nfsd4_op *op) 
		goto status;

	BUG_ON(op->opnum < 0 || op->opnum >= ARRAY_SIZE(nfsd4_enc_ops) ||

	       !nfsd4_enc_ops[op->opnum]);

	op->status = nfsd4_enc_ops[op->opnum](resp, op->status, &op->u);

	encoder = nfsd4_enc_ops[op->opnum];

	op->status = encoder(resp, op->status, &op->u);

	/* nfsd4_check_resp_size guarantees enough room for error status */

	if (!op->status)

		op->status = nfsd4_check_resp_size(resp, 0);

	if (op->status == nfserr_resource ||

	    op->status == nfserr_rep_too_big ||

	    op->status == nfserr_rep_too_big_to_cache) {

		/*

		 * The operation may have already been encoded or

		 * partially encoded.  No op returns anything additional

		 * in the case of one of these three errors, so we can

		 * just truncate back to after the status.  But it's a

		 * bug if we had to do this on a non-idempotent op:

		 */

		warn_on_nonidempotent_op(op);

		resp->xdr.p = statp + 1;

	}

	if (so) {

		so->so_replay.rp_status = op->status;

		so->so_replay.rp_buflen = (char *)resp->xdr.p

fs/nfsd/xdr4.h

+2 −0
Original line number Diff line number Diff line
@@ -536,6 +536,8 @@ static inline bool nfsd4_last_compound_op(struct svc_rqst *rqstp) 
	return argp->opcnt == resp->opcnt;

}



void warn_on_nonidempotent_op(struct nfsd4_op *op);



#define NFS4_SVC_XDRSIZE		sizeof(struct nfsd4_compoundargs)



static inline void