Commit b4687da7 authored by Chuck Lever's avatar Chuck Lever Committed by Trond Myklebust
Browse files

SUNRPC: Refactor logic to NUL-terminate strings in pages 



Clean up: Introduce a helper to '\0'-terminate XDR strings
that are placed in a page in the page cache.

Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent 38359352

fs/nfs/nfs2xdr.c

+1 −5
Original line number Diff line number Diff line
@@ -596,7 +596,6 @@ nfs_xdr_readlinkres(struct rpc_rqst *req, __be32 *p, void *dummy) 
	struct kvec *iov = rcvbuf->head;

	size_t hdrlen;

	u32 len, recvd;

	char	*kaddr;

	int	status;



	if ((status = ntohl(*p++)))
@@ -623,10 +622,7 @@ nfs_xdr_readlinkres(struct rpc_rqst *req, __be32 *p, void *dummy) 
		return -EIO;

	}



	/* NULL terminate the string we got */

	kaddr = (char *)kmap_atomic(rcvbuf->pages[0], KM_USER0);

	kaddr[len+rcvbuf->page_base] = '\0';

	kunmap_atomic(kaddr, KM_USER0);

	xdr_terminate_string(rcvbuf, len);

	return 0;

}

fs/nfs/nfs3xdr.c

+1 −5
Original line number Diff line number Diff line
@@ -824,7 +824,6 @@ nfs3_xdr_readlinkres(struct rpc_rqst *req, __be32 *p, struct nfs_fattr *fattr) 
	struct kvec *iov = rcvbuf->head;

	size_t hdrlen;

	u32 len, recvd;

	char	*kaddr;

	int	status;



	status = ntohl(*p++);
@@ -857,10 +856,7 @@ nfs3_xdr_readlinkres(struct rpc_rqst *req, __be32 *p, struct nfs_fattr *fattr) 
		return -EIO;

	}



	/* NULL terminate the string we got */

	kaddr = (char*)kmap_atomic(rcvbuf->pages[0], KM_USER0);

	kaddr[len+rcvbuf->page_base] = '\0';

	kunmap_atomic(kaddr, KM_USER0);

	xdr_terminate_string(rcvbuf, len);

	return 0;

}

fs/nfs/nfs4xdr.c

+1 −4
Original line number Diff line number Diff line
@@ -4299,7 +4299,6 @@ static int decode_readlink(struct xdr_stream *xdr, struct rpc_rqst *req) 
	size_t hdrlen;

	u32 len, recvd;

	__be32 *p;

	char *kaddr;

	int status;



	status = decode_op_hdr(xdr, OP_READLINK);
@@ -4330,9 +4329,7 @@ static int decode_readlink(struct xdr_stream *xdr, struct rpc_rqst *req) 
	 * and and null-terminate the text (the VFS expects

	 * null-termination).

	 */

	kaddr = (char *)kmap_atomic(rcvbuf->pages[0], KM_USER0);

	kaddr[len+rcvbuf->page_base] = '\0';

	kunmap_atomic(kaddr, KM_USER0);

	xdr_terminate_string(rcvbuf, len);

	return 0;

out_overflow:

	print_overflow_msg(__func__, xdr);

include/linux/sunrpc/xdr.h

+1 −0
Original line number Diff line number Diff line
@@ -108,6 +108,7 @@ void xdr_encode_pages(struct xdr_buf *, struct page **, unsigned int, 
			 unsigned int);

void	xdr_inline_pages(struct xdr_buf *, unsigned int,

			 struct page **, unsigned int, unsigned int);

void	xdr_terminate_string(struct xdr_buf *, const u32);



static inline __be32 *xdr_encode_array(__be32 *p, const void *s, unsigned int len)

{

net/sunrpc/xdr.c

+17 −0
Original line number Diff line number Diff line
@@ -111,6 +111,23 @@ xdr_decode_string_inplace(__be32 *p, char **sp, 
}

EXPORT_SYMBOL_GPL(xdr_decode_string_inplace);



/**

 * xdr_terminate_string - '\0'-terminate a string residing in an xdr_buf

 * @buf: XDR buffer where string resides

 * @len: length of string, in bytes

 *

 */

void

xdr_terminate_string(struct xdr_buf *buf, const u32 len)

{

	char *kaddr;



	kaddr = kmap_atomic(buf->pages[0], KM_USER0);

	kaddr[buf->page_base + len] = '\0';

	kunmap_atomic(kaddr, KM_USER0);

}

EXPORT_SYMBOL(xdr_terminate_string);



void

xdr_encode_pages(struct xdr_buf *xdr, struct page **pages, unsigned int base,

		 unsigned int len)

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