From b4687da7fc5f741af7fee9b0248a2cf2ad9c4478 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Tue, 21 Sep 2010 16:55:48 -0400 Subject: [PATCH] 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: Chuck Lever Signed-off-by: Trond Myklebust --- fs/nfs/nfs2xdr.c | 6 +----- fs/nfs/nfs3xdr.c | 6 +----- fs/nfs/nfs4xdr.c | 5 +---- include/linux/sunrpc/xdr.h | 1 + net/sunrpc/xdr.c | 17 +++++++++++++++++ 5 files changed, 21 insertions(+), 14 deletions(-) diff --git a/fs/nfs/nfs2xdr.c b/fs/nfs/nfs2xdr.c index e15bc0306d0c..79c74387a2fe 100644 --- a/fs/nfs/nfs2xdr.c +++ b/fs/nfs/nfs2xdr.c @@ -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; } diff --git a/fs/nfs/nfs3xdr.c b/fs/nfs/nfs3xdr.c index 89c40f8ec6e6..52b2fda66e63 100644 --- a/fs/nfs/nfs3xdr.c +++ b/fs/nfs/nfs3xdr.c @@ -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; } diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c index b0bd7efe8100..86ab69eb149c 100644 --- a/fs/nfs/nfs4xdr.c +++ b/fs/nfs/nfs4xdr.c @@ -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); diff --git a/include/linux/sunrpc/xdr.h b/include/linux/sunrpc/xdr.h index 35cf2e8cd7c6..8c1dcbb54d89 100644 --- a/include/linux/sunrpc/xdr.h +++ b/include/linux/sunrpc/xdr.h @@ -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) { diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c index 3bbef7f5f826..e0725d9d8107 100644 --- a/net/sunrpc/xdr.c +++ b/net/sunrpc/xdr.c @@ -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) -- 2.20.1