[PATCH] kNFSd - 1 of 2 - Change NFSv4 xdr decoding to cope with separate pages.

Now that nfsd uses a list of pages for requests instead of
one large buffer, NFSv4 need to know about this.

The most interesting part of this is that it is possible
that section of a request, like a path name, could span
two pages, so we need to be able to kmalloc as little bit
of space to copy them into, and make sure they get
freed later.

fs/nfsd/nfs4proc.c

@@ -481,7 +481,8 @@ nfsd4_write(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_writ
 	*p++ = nfssvc_boot.tv_usec;
 
 	return nfsd_write(rqstp, current_fh, write->wr_offset,
-			  write->wr_buf, write->wr_buflen, &write->wr_how_written);
+			  write->wr_vec, write->wr_vlen, write->wr_buflen,
+			  &write->wr_how_written);
 }
 
 /* This routine never returns NFS_OK!  If there are no other errors, it
@@ -700,6 +701,16 @@ nfsd4_proc_compound(struct svc_rqst *rqstp,
 		kfree(args->ops);
 		args->ops = args->iops;
 	}
+	if (args->tmpp) {
+		kfree(args->tmpp);
+		args->tmpp = NULL;
+	}
+	while (args->to_free) {
+		struct tmpbuf *tb = args->to_free;
+		args->to_free = tb->next;
+		kfree(tb->buf);
+		kfree(tb);
+	}
 	fh_put(&current_fh);
 	fh_put(&save_fh);
 	return status;

include/linux/nfsd/xdr4.h

@@ -249,7 +249,9 @@ struct nfsd4_write {
 	u64		wr_offset;          /* request */
 	u32		wr_stable_how;      /* request */
 	u32		wr_buflen;          /* request */
-	char *		wr_buf;             /* request */
+	struct iovec	wr_vec[RPCSVC_MAXPAGES]; /* request */
+	int		wr_vlen;
+
 	u32		wr_bytes_written;   /* response */
 	u32		wr_how_written;     /* response */
 	nfs4_verifier	wr_verifier;        /* response */
@@ -288,6 +290,14 @@ struct nfsd4_compoundargs {
 	/* scratch variables for XDR decode */
 	u32 *				p;
 	u32 *				end;
+	struct page **			pagelist;
+	int				pagelen;
+	u32				tmp[8];
+	u32 *				tmpp;
+	struct tmpbuf {
+		struct tmpbuf *next;
+		void *buf;
+	}				*to_free;
 	
 	u32				taglen;
 	char *				tag;