gfs_pio_write() writes up to size bytes to the file gf from the buffer starting at buffer. It returns the number of bytes written to the address pointed by np.
GFARM_ERR_NO_ERROR
The function terminated successfully.
GFARM_ERR_OPERATION_NOT_PERMITTED
gf does not specify a regular file.
GFARM_ERR_BAD_FILE_DESCRIPTOR
The file descripter specified by gfp is not a valid or is not open for writing.
GFARM_ERR_NO_SPACE
The file system node has no room to store data
GFARM_ERR_NO_FILE_SYSTEM_NODE
There is no available file system node.
GFARM_ERR_NO_MEMORY
Insufficient memory was available.
An error except the above occurred. The reason is shown by gfarm_error_string(3).