add DFS_NFS_MAX_MTU to nfs to support read/write more than one mtu data in nfs; 2) fix a bug in nfs_lseek when offset is at the end of file.

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@2485 bbd45198-f89e-11dd-88c7-29a3b14d5316

components/dfs/filesystems/nfs/dfs_nfs.c

@@ -22,6 +22,11 @@
 #include "nfs.h"
 
 #define NAME_MAX	64
+#define DFS_NFS_MAX_MTU  1024
+
+#ifdef _WIN32
+#define strtok_r strtok_s
+#endif
 
 struct nfs_file
 {
@@ -532,7 +537,7 @@ int nfs_read(struct dfs_fd *file, void *buf, rt_size_t count)
 {
 	READ3args args;
 	READ3res res;
-	ssize_t bytes;
+	ssize_t bytes, total=0;
 	nfs_file *fd;
 	struct nfs_filesystem *nfs;
 
@@ -553,43 +558,52 @@ int nfs_read(struct dfs_fd *file, void *buf, rt_size_t count)
 		return 0;
 
 	args.file = fd->handle;
+	do {
 		args.offset = fd->offset;
-	args.count = count;
+		args.count = count > DFS_NFS_MAX_MTU ? DFS_NFS_MAX_MTU : count;
+		count -= args.count;
 
 		memset(&res, 0, sizeof(res));
 		if (nfsproc3_read_3(args, &res, nfs->nfs_client) != RPC_SUCCESS)
 		{
 			rt_kprintf("Read failed\n");
-		bytes = 0;
+			total = 0;
+			break;
 		}
 		else if (res.status != NFS3_OK)
 		{
 			rt_kprintf("Read failed: %d\n", res.status);
-		bytes = 0;
+			total = 0;
+			break;
 		}
 		else
 		{
-		if (res.READ3res_u.resok.eof)
-		{
-			/* something should probably be here */
-			fd->eof = TRUE;
-		}
 			bytes = res.READ3res_u.resok.count;
+			total += bytes;
 			fd->offset += bytes;
 			/* update current position */
 			file->pos = fd->offset;
 			memcpy(buf, res.READ3res_u.resok.data.data_val, bytes);
+			buf = (void *)((char *)buf + args.count);
+			if (res.READ3res_u.resok.eof)
+			{
+				/* something should probably be here */
+				fd->eof = TRUE;
+				break;
+			}
 		}
 		xdr_free((xdrproc_t)xdr_READ3res, (char *)&res);
+	} while(count > 0);
 
-	return bytes;
+	xdr_free((xdrproc_t)xdr_READ3res, (char *)&res);
+	return total;
 }
 
 int nfs_write(struct dfs_fd *file, const void *buf, rt_size_t count)
 {
 	WRITE3args args;
 	WRITE3res res;
-	ssize_t bytes;
+	ssize_t bytes, total=0;
 	nfs_file *fd;
 	struct nfs_filesystem *nfs;
 
@@ -607,33 +621,43 @@ int nfs_write(struct dfs_fd *file, const void *buf, rt_size_t count)
 
 	args.file = fd->handle;
 	args.stable = FILE_SYNC;
+
+	do {
 		args.offset = fd->offset;
 
 		memset(&res, 0, sizeof(res));
 		args.data.data_val=(void *)buf;
-	args.count=args.data.data_len = count;
+		args.count = count > DFS_NFS_MAX_MTU ? DFS_NFS_MAX_MTU : count;
+		args.data.data_len = args.count;
+		count -= args.count;
+		buf = (const void *)((char *)buf + args.count);
 
 		if (nfsproc3_write_3(args, &res, nfs->nfs_client) != RPC_SUCCESS)
 		{
 			rt_kprintf("Write failed\n");
-		bytes = 0;
+			total = 0;
+			break;
 		}
 		else if (res.status != NFS3_OK)
 		{
 			rt_kprintf("Write failed: %d\n", res.status);
-		bytes = 0;
+			total = 0;
+			break;
 		}
 		else
 		{
 			bytes = res.WRITE3res_u.resok.count;
 			fd->offset += bytes;
+			total += bytes;
 			/* update current position */
 			file->pos = fd->offset;
 			/* todo: update file size */
 		}
 		xdr_free((xdrproc_t)xdr_WRITE3res, (char *)&res);
+	} while (count > 0);
 
-	return bytes;
+	xdr_free((xdrproc_t)xdr_WRITE3res, (char *)&res);
+	return total;
 }
 
 int nfs_lseek(struct dfs_fd *file, rt_off_t offset)
@@ -646,7 +670,7 @@ int nfs_lseek(struct dfs_fd *file, rt_off_t offset)
 	fd = (nfs_file *)(file->data);
 	RT_ASSERT(fd != RT_NULL);
 
-	if (offset < fd->size)
+	if (offset <= fd->size)
 	{
 		fd->offset = offset;
 		return offset;