fix lseek issue.

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@1032 bbd45198-f89e-11dd-88c7-29a3b14d5316

components/dfs/filesystems/elmfat/dfs_elm.c

@@ -364,8 +364,9 @@ int dfs_elm_write(struct dfs_fd* file, const void* buf, rt_size_t len)
 	RT_ASSERT(fd != RT_NULL);
 
 	result = f_write(fd, buf, len, &byte_write);
-	/* update position */
+	/* update position and file size */
 	file->pos  = fd->fptr;
+	file->size = fd->fsize;
 	if (result == FR_OK) return byte_write;
 
 	return elm_result_to_dfs(result);
@@ -392,6 +393,11 @@ int dfs_elm_lseek(struct dfs_fd* file, rt_off_t offset)
 	RT_ASSERT(fd != RT_NULL);
 
 	result = f_lseek(fd, offset);
+	if (result == FR_OK)
+	{
+		/* return current position */
+		return fd->fptr;
+	}
 	return elm_result_to_dfs(result);
 }
 

components/dfs/filesystems/nfs/dfs_nfs.c

@@ -557,6 +557,8 @@ int nfs_read(struct dfs_fd* file, void *buf, rt_size_t count)
 		}
 		bytes=res.READ3res_u.resok.count;
 		fd->offset += bytes;
+		/* update current position */
+		file->pos = fd->offset;
 		memcpy(buf, res.READ3res_u.resok.data.data_val, bytes);
 	}
 	xdr_free((xdrproc_t)xdr_READ3res, (char *)&res);
@@ -606,6 +608,9 @@ int nfs_write(struct dfs_fd* file, const void *buf, rt_size_t count)
 	{
 		bytes=res.WRITE3res_u.resok.count;
 		fd->offset+=bytes;
+		/* update current position */
+		file->pos = fd->offset;
+		/* todo: update file size */
 	}
 	xdr_free((xdrproc_t)xdr_WRITE3res, (char *)&res);
 

components/dfs/src/dfs_file.c

@@ -290,12 +290,19 @@ int dfs_file_flush(struct dfs_fd* fd)
  */
 int dfs_file_lseek(struct dfs_fd* fd, rt_off_t offset)
 {
+	int result;
 	struct dfs_filesystem* fs = fd->fs;
 
 	if (fd == RT_NULL) return -DFS_STATUS_EINVAL;
 	if (fs->ops->lseek == RT_NULL) return -DFS_STATUS_ENOSYS;
 
-	return fs->ops->lseek(fd, offset);
+	result = fs->ops->lseek(fd, offset);
+
+	/* update current position */
+	if (result >= 0)
+		fd->pos = result;
+
+	return result;
 }
 
 /**